Li 'The Serpent' Ping, is a member of the Council, the owner of the casino "Hydra", expert hand-to-hand combatant, martial artist and Council's bodyguard.
As revealed in the fourth season of the series, he is the biological older brother of Lee Ping and the long-lost first son to the Pings. He tends to mess with the minds of his biological family and their friends.
The baby who would one day become known as "The Serpent" was born in 1992 to Sue and Alfred Ping in Korea. At least two pictures of his infancy were taken before his kidnapping.
At the behest of His Eminence, the young baby Li was abducted by Cassandra who knew nothing about Li's family relations or his blood ties to the Pings. Cassandra was the one who was put in charge of training the child to be the council's personal enforcer. According to the creators, Li "was raised in almost a dungeon-type atmosphere as a kid in the garbage pit of Coral Grove". On his first mission, Li earned the nickname "The Serpent" by inventing a new deadly move: the Serpent Strike. Early on in his work, he got his hands on an ancient medallion that had a Tatzelwurm-representing Red and Blue Yin-Yang design. Though this part of his early life is clear, there are still unknown points in time in what he did, either taking over or opening up his own casino; getting a snake who he then trained; discovering his true origins from His Eminence after which he began to conspire against Cassandra for robbing him of his family.
During Victoria's demonstration of her brainwashing research the Serpent was present and watching the demonstration unaffected by the Prank Song's effects. When his brother stopped the plot of the vice principal he moved to capture her and take her away with the other council members to Coral Grove.
When the Blue Cyborg Tatzelwurms began to malfunction the Serpent moved to defeat them all with ease, while jokingly making a coin-flip statement in the process. He retreated when the replicated key exploded covering the council's escape.
In season 4 he started to become a much more recurring antagonist, actively stalking Lee and his family and confronting him on numerous occasions during which he revealed more and more of himself to Lee, finally coming to his father, Alfred, and confirming he is Lee's brother
here are instances where he can withhold information for his own benefit, showing that he is not a devoted follower to the council, or at least has his own agenda to follow, which once again only furthers his mysteriousness. He may have some concern for Lee, or at least Lee's activities. As when Finnwich hid the book in the episode "Follow that Finnwich", the Serpent saw Lee recover the book. But he chose not to reveal that information to his boss, Cassandra.
The Serpent has also shown that he holds great pride in his martial arts skills taunting Lee by saying, "Even half-blind I am still 10 times the warrior that you are." So it can be concluded that he sees Lee as a rival. However this pride sometimes leans towards arrogance to the point that he even revealed his identity right after he had gotten a strand of Lee's hair. This and a DNA test he prerormed at the end of "Splitting Hairs" seems to imply that his interest in Lee may be more self-beneficial.
He is a very good gamer, and enjoys such things very much. There is a bit of a sadistic side to him, when he teased Biffy, Holger, and Cam about being eaten by a snake, and scaring them to play fifty-two pickup. Further demonstrating his sadism was when he enjoyed tormenting Lee in a game of cat and mouse beneath his casino.
He is also an expert manipulator and seems to have a penchant for convoluted plots. He has shown to be quite the lady's man when the need arises as well. He offered Jenny Jenkins a ride to school, just to initiate an outbreak of head lice and acquire a strand of Lee's hair so he can ereform DNA tests on the hair. However,r when something unexpected comes along the Serpent shows a side to him that tends to panic when a random factor throws his plots off course showing that despite his pride and arrogance he is not above recognizing a dangerous situation when one arises.
When first shown in the Dance part 2, he grabbed and detailed Vice Principle Victoria with just one hand. This instance also showed immunity to the prank song and thus shows he can't be brainwashed.
The Serpent tends to take on an enforcer role in the council. He has shown to be able of great physical and superhuman feats, capable of taking down five blue Tazelwurms without much difficulty, and fend off several more while he and the rest of the council escape. ("All That Taz"). He has shown to have reflexes and agility as well as precision that outmatch Biffy Goldstein. ("The Hydra"). He has also shown considerably high jumping skills ("Splitting Hairs") and agility and speed to match. He can also drive a motorcycle.
As the owner of the Hydra Casino, he has absolute authority over the operation that it entails, regardless of anything that anyone else can do about it, and even if it breaks the law, ("The Hydra"), as seen when he ordered three minors into his personal office to gamble despite it being illegal.
He is an expert in several types of games and is very good at them.
His duties within the Council are not simply limited to enforcement however, and his jack-of-all-trades skill set makes him a valued asset, even earning the respect of Cassandra McAdams, something that she has not shown to give to the other members, (at least not the unnamed woman and her brother). However from the beginning, he was been working behind her back at the behest of the council's true leader and even though she eventually found out, he still kept it hidden for a considerable amount of time before being discovered. The fact that the council leader himself has a good deal of faith in his abilities speaks but volumes of what the serpent is capable of.
He seems to be a good stylist, as he styled Mrs. Ping's hair, as well as a stalker and cameraman, keeping tabs on Lee's family without their knowledge for weeks, and it was not until Lee spied it through his camera that he discovered this ("Splitting Hairs").
In addition, he is an expert at covert and espionage. He disguised himself as a nurse to check for lice, and the fact that he could do that seems to suggest at least some medical knowledge in regards to the scalp on his part ("Splitting Hairs").
The Serpent is a very good planner, manipulator and thinker, performing convoluted and effective plans all for a grand and larger scheme of his and the council's. He caused an outbreak of lice just to get a sample of Lee's DNA (Splitting Hairs). When his plans start to fall apart he can improvise as well, blending into a crowd, and jumping into an air vent for example.
Priscilla, the Serpent's pet snake, is trained to do extremely difficult tasks, like attacking the opponents by her master's command and fighting by his side, as seen in "Band of Heroes".
The Serpent is reasonably over confident in his abilities and often underestimates his opponents. Additionally, he is severely allergic to fish, swelling quite severely whenever fish or fish products are applied on his skin. Apparently these rashes are short-lived however. He shares the Fish allergy with Alfred Ping. This and other similarities suggest a relationship between the two but Lee doesn't have fish allergies.
- Lee Ping: they are revealed to be biological brothers. Li seems to hate Lee for getting the tattoo over his birthmark that Alfred Ping gave Lee instead of him. This jealousy extends to the point that he is not above ambushing Lee underground and messing with him or tormenting Lee's friends and loved ones. In "The Serpent Strike" Li mocks Lee by saying he is "nothing, but a half-rate copy [of him]", hinting at the fact that the Pings 'replaced' their missing son with Lee. Li is obviously bitter at the fact that he was robbed of a peaceful childhood while Lee grew up with his loving parents, what results in Li viewing his brother as a "spoiled kid". Though Li has attacked his brother on more than one occasion, he still seems to have a certain amount of concern for him, allowing him to keep the book while lying to his superiors about it despite the risk, letting Lee and his friends sneak out of the underground unwitnessed and rescuing his gang from the imprisonment right before confronting Cassandra to win Lee some time. Lee is mostly confused with Li's attitude to him, viewing him as a powerful and dangerous enemy, but after the reveal of their relation Lee showed mild concern over his brother's defeat at Casandra's hands.
- Alfred Ping: Alfred is revealed to be Li's biological father in "Mummy Ping and the Snake Man of Evil". Alfred seemed to suspect the Serpent being his long-lost son, as he was warning Lee "not to trust him [the Serpent]". He didn't ever explain why he hadn't tattooed Li as a child. As shown through Cassandra and His Eminence's conversation, Alfred had a private meeting with His Eminence and Li after the events of "Mummy Ping And The Snake Man of Evil", however the details of this meeting are left unclear.
- Sue Ping: the clone of Li's biological mother. She seemed not to recongize Li while at the hairstyling saloon, probably due to never knowing about him in the first place, as she seemingly was cloned sometime after Lee was born/raised.
- Cassandra McAdams: the Serpent's boss as she is head of the Council. While she does show some respect for him, it is only for his usefulness to her. Likewise, the Serpent may see Cassandra as a means to his own ends as well. In "Band of Heroes", in a fight between her and the Serpent, they reveal that Cassandra raised him after he was taken from his real family, to which the Serpent replies that all she taught him "to hate". She was the one who took care of the Serpent, raised him and taught him to fight, but only used him as her personal bodyguard and an assassin. As of "Mannifestum Rising", Cassandra did not know the Serpent was Lee's brother or was related to the Pings.
- Priscilla: The only person (though a snake) that he shows any kind of true affection for. Li is seen especially outraged if anyone dares to hurt or threaten her.
- Jenny Jergens: The Serpent seduced Jenny and used her in order to get the Manifesto Arcanuous by orders of the Council. The Serpent hid her bike and set everything up to make it look like he actually found it, in order to win her trust. On their "date" the Serpent finally takes the book, after which he leaves Jenny heartbroken and terrified in the woods. In Mummy Ping and the Snake Man of Evil, he mockingly tells a patient he mistakes for Mr. Ping, "There is a girl that I like, and gosh darn, I don't know if she likes me.", alluding to Jenny. Additionally, Cassandra sarcastingly calls Jenny Li's 'girlfriend'.
- His Eminence: revealed the Serpent's identity to him. He may or may not have had the Serpent separated from his family to begin with, but he did arrange for Cassandra to be in charge of his care. The Serpent becomes his co-conspirator to get revenge on Cassandra. When he is captured His Eminence orders Cassandra to release him.
- "I have something you want. But the crazy part is, I want it too. So, why don't we play for it?" - "The Hydra"
- "Boys, this is a casino. We take our games very seriously here." - "The Hydra"
- "Ah. But it's not your turn to pick. It's mine. So, what will I choose? Hmm. Interesting suggestion." - "The Hydra"
- Lee: "Hey. How come you don't stink anymore?"
The Serpent: "How come you don't stink anymore?" - "Splitting Hairs"
- Lee: "What? Okay, I know you're a gold medal class weirdo, but why do you have that?"
The Serpent: "Wouldn't you like to know." - "Splitting Hairs"
- "It's so fun to make them sweat." - "Enter the Serpent"
- "Make them wait. Suspense, building... 'Oh no! What will they do with me!' Suspense. Something for both the hunter and the hunted to enjoy." - "Enter the Serpent"
- "I should've known a spoiled kid would be no competition." - "Enter the Serpent"
- "Even half-blind I'm still ten times the warrior you are, Lee Ping!" - "Enter the Serpent"
- "Hi. I'm The Serpent. That's right, the mysterious casino owner with a pet snake named Priscilla. You've heard of me, right? I got my name when I passed my very first test. Heehee! That was back when I came up with a deadly move called The Serpent's Strike. Trust me, you don't ever want it coming your way." - "Revenge of the Cycle Killers"
- "I heard Lee Ping calls me Stink Ninja. Funny fellow. Wanna know where the smell comes from? Can you keep a secret? It's my ancient medallion, worn by the greatest warriors, handed down for thousands of years. That's a lot of blood, sweat and death my friend. I suppose now you want to know more. Aside from what I'm doing at the casino, and for Cassandra, I'm on my own mission. And I now have all my facts. But how will I...use them?" - "Revenge of the Cycle Killers"
- "I never kinda do a lot of things." - "Revenge of the Cycle Killers"
- Jenny: "Ha ha woo hoo! Ah, you were right. Riding my bike after a rainstorm does cheer me up."
The Serpent: "Dear diary, today I stopped holding my friend's hand and actually had fun!"
Jenny: "Feh, as if I keep a diary. That's like so ninth grade."
The Serpent: "Really?"
Jenny: "I'm in tenth grade."
The Serpent: "Could've fooled me." -"Revenge of the Cycle Killers"
- "Okay, big daddy Ping. Reunion time." - "Serpent Strike"
- "Fate saves you again. Pings." - "Serpent Strike"
- Jenny: "Has anyone ever told you you're kinda freaky?"
The Serpent: "Once. Technically twice, but things didn't end well for him or his loud parrot." - "Serpent Strike"
- The Serpent: [about the Mark] "It reminds you of someone you know, doesn't it. Lee Ping, perhaps."
Jenny: "Yeah. Wait, how do you know him?"
The Serpent: "Oh I know a lot of things, Jenny Jergens." - "Serpent Strike"
- "The unfinished business I have is with dear ol' Daddy Ping. [to Lee] I'll tell him you say hi. Oh, and where are my manners? Priscilla! We have guests." - "Serpent Strike"
- "Is the gentleman or missus of the house home?" [maniacal giggle] - "Serpent Strike"
- The Serpent: "Hello? How are you and Priscilla getting along?"
Lee: "Yeah. Who names their snake that?"
The Serpent: "When she hugs you tight, and your ribs start to go pop pop pop, I want you to remember. You're nothing but a half-rate copy of me." - "Serpent Strike"
- "Whoa, someone is extra allergic to fish, huh? Guess it runs in the family! Might wanna try moisturizer for the hives, instead of wrapping yourself up like a mummy. You know like normal people do?" - "Mummy Ping and the Snake Man of Evil"
- "Okay Doctor Ping, let's have that father-son chat we never had. So, I met this girl, and well, gosh darn, I like her and how do I tell if she likes me? Just kidding. Let's go back further than that. To around, this time." - "Mummy Ping and the Snake Man of Evil"
- Lee: "Nineteen ninety-two? But I was born in nineteen ninety-seven."
The Serpent: "Ah, but I was born in nineteen ninety-two. Not everything is about you, Lee Ping." - "Mummy Ping and the Snake Man of Evil"
- "If I'm not who I say I am then why do I know that your father added a tattoo to your birthmark, and you added the same protection to him? But not me! [to Alfred Ping] Why was that?!?" - "Mummy Ping and the Snake Man of Evil"
- "Don't spoil the family reunion, boys. It's been so nice up to now. Stay here, and maybe we can catch up a little later. Okay, bro?" - "Mummy Ping and the Snake Man of Evil"
- "Look Priscilla. We have guests. And they didn't even buzz up to say 'Hello. Sorry about stealing you away from your family and making you into a warrior of vengeance.'" - "Band of Heroes"
- Lee: [sour] "You caught me. Now what?"
The Serpent: "Please. I've got bigger fish to fry today. Bro." - "Band of Heroes"
- Cassandra: "Did you really think it would be that easy?"
The Serpent: "Um. Yes. But that was before now." - "Band of Heroes"
- "You can mess with me all you want! But no one messes with Priscilla!" - "Band of Heroes"
- Cassandra: How long have you been working behind my back?"
The Serpent: "Since [His Eminence] told me I have a real family and you took me from them!" - "Band of Heroes"
- "All you did was teach me to hate! And train me to be your spooky little assassin!" - "Band of Heroes"
- In "Mummy Ping And The Snake Man Of Evil", it was revealed that Li is 5 years older than Lee, being born in 1992, what makes Li 20 years old at the time of the show's events.
- He bears a strong physical resemblance to Lee Ping as well as to their grandfather, Lo Ping, making Li the closest member of Ping family to resemble him.
- As of reasons unknown, Alfred didn't cover Li's Mark of His Eminence with a tattoo when he was born. That gave Li a drive to confront his father and get the answer to that question, but Alfred still never told the truth.
- Li has a blue strand of hair that contrasts Lee's red-and-black hair. This is a recurring colouration motif since the start of the series, that is most notable in the design of Tazelwurms, the back of the mysterious book (The Red and Blue Tazelwurms in the shape of the Ying-Yang symbol) and the pyramid's colour scheme switching from red to blue. This is rather symbolic and likewise empathizes the connection between the brothers being on opposite sides: one being the council's enforcer trying to conceal their actions and the other investigating and revealing them.
- Lee, Li and Alfred are seemingly based off of the Korean Deities Sobyeol, Daebyeol, and their father, Cheonjiwang. Sobyeol had a competition with his elder brother Daebyeol to see who would rule the mortal world and nether worlds respectively. Sobyeol became the ruler of the mortal world which reflects Lee Ping living a normal life until the prank, while Daebyeol ruled the netherworld befitting Li's role as an assassin.
- In "Enter the Serpent", he mentions his snake's name is "Priscilla".
- The cloned Mrs. Ping (Sue Ping) referred to the Serpent as 'hot' in "Fight or Flight".
- In 'The Hydra', when Biffy, Cam and Holger get intimidated by his snake, he tells (by technical mistake) not to mind 'him' (the snake), but later says 'I've noticed 'she' really likes you [Cam]'.
- When he played the games with Biffy, Cam, and Holger, he told them (or rather implied that) if they lost they would be food to his pet snake. This is impossible, for a snake of that size to eat a humans of the size of Holger, Biffy or Cam (mainly Biffy), meaning that he was probably just messing with them.
- Li makes an appearance in the season 3 trailer towards the end as Lee walks into the school, watching his brother behind a tree.
- As inheriting from his father, Li is allergic to fish. He quickly swells when tasting fish-containing food or applying fish products to his skin.
- At the end of "Splitting Hairs" Li gets a strand of Lee Pings hair and monologues about "finally finding Lee", which must mean he has been searching for him for a while. In "Serpent Strike", Li calls Lee "a half-rate copy of [him]", suggesting to the audience and Lee that the latter is the Serpent's clone. Then, in "Mummy Ping And The Snake Man Of Evil" Li jokingly calls Lee "bro", confirming the blood relation of the two. He continues to call Lee bro in "Band Of Heroes".
- Li turned to Lee's side from of "Band Of Heroes" as he was actually working undercover for Cassandra. When a fight issued between them it was revealed that it was Cassandra who trained him to be on her side all along. Because Li eventually betrayed her plotting His Eminence's plan behind her back, she had him sent off to Coral Grove.
- Charles Johnston, co-creator of the show, confirmed on Twitter (traces of that interview are now lost) that the Serpent's first name is Li.