Even after 25 years, comic-book artist Rob Liefeld still can’t home in on a single reason exactly why Deadpool, Marvel's resident "Merc with a Mouth" and Hollywood’s spankin’-new movie star, is so popular among fans.br Instead, there are quite a few.br He has a neato red-and-black outfit.br He breaks the fourth wall regularly.br He does serious damage with guns and katana swords.br He lives for chimichangas and Bea Arthur.br And he’s a total wisenheimer.br The antihero doesn’t have the mainstream recognition of Captain America or Batman, but that could change with Deadpool (in theaters Friday), directed by Tim Miller.br The R-rated action comedy stars Ryan Reynolds as Wade Wilson, who turns to some shady figures to cure his cancer and ends up a wisecracking disfigured warrior with an obscenely good healing factor.br So Deadpool isn't exactly a patriotic super-soldier like Cap or a muscular thunder god like Thor.