Batman/Robin Hood

Heroes
Bruce Wayne/Batman as Robin Hood

Dick Grayson/Robin as Little John

Terry McGinnis/Batman Beyond as Allan-A-Dale (sounds funny, doesn't it?)

Villains
The Joker as Prince John

Waylon Jones/Killer Croc as Friar Tuck

Selina Kyle/Catwoman as Maid Marian

Dr. Pamela Lillian Isley/Poison Ivy as Lady Cluck

Harvey Dent/Two-Face as Skippy