Dewey was the mascot of the Coney Island Dominators, in The Warriors novel.
In The Novel[]
Dewey is the mascot of the gang, even though Dewey outranks Hinton, he is instead picked as the new leader.
In The Film[]
Cochise could be seen as a replacement for Dewey, as Dewey is the mascot, so Cochise could be seen as a mascot for his very tribal appearance that makes him stand out most.