Earl's picture
Earl Nigma was the brother of Alexander Nigma and the presumably the first janitor of A Nigma High.
History
Before the series
There is a painting of him in room 113B, which appears similar to a janitor's closet, further indicating that he was a janitor. His painting appears in The Theme Team and again (albeit quickly) in The Dance Part 1. In The Curse of Earl Nigma it is revealed that Earl Nigma was a gifted fencer but stumbled at one point during a tournament and ever since the A Nigma fencing team has been cursed to lose. Since Chaz is the source of this information its accuracy is highly suspect.
Gallery
His Nameplate
Earl and Alexander Nigma