Dang is a janitor that works for Finnegan High. He is very skilled at martial arts, popping out of nowhere when the characters mention his name. Occasionally he wears a giant purple cowboy hat with feathers, which he calls his "Fancy Hat". He lives in Finnegan High and almost never wants to leave because leaf monkeys don't live there, who steal his fancy hat. A running gag is when ever someone says his name he apears out of nowhere (even in a virtual world), even though they didn't mean it.
Dang has a brother named Ding that he dislikes because Ding married a duck named Shirley. Dang forgave his brother (not in person, Echo was disguised as Ding unintentionally) because he saw Slab's mother saying "There are worse things to marry than duck!" mentioned in the episode "Mr. DNA".
It is revealed in Mr. Time that Dang's ability to pop out of nowhere is thanks to his ability to slow down time, at the exact same speed as the machine that Adam created in the same episode. He is seen to walk around at normal speed, weaving between Echo and Mr. Tater, who are stuck in a slower time. To Adam and Derby, he is seen normally, as they are in a room which has extremely accelerated time, however to anyone else he can not be seen as he moves so fast.
Principal Tater - Dang and Tater have respect for one another. They appear to be friends outside of school, as Tater allowed Dang to come with him to Sanduras in "Mr. Spring Break". He is also annoyed with Principal Tater as shown in Mr. Invisible.