Tony
Having rewatched the movie as an adult after maybe 20 years of not seeing it, I still really like it for its unique take on the immigrant experience that appealed to both my younger and older self.
But did anyone else notice that the character of Tony is kind of a douchebag? I'm trying to think, did he ever actually do any good for Fievel? It seems like even when he tried to help, he was always distracted by his raging hard-on for Bridget. Especially when he and Fievel woke up late for the secret plan and he took it out on Fievel saying "Why didn't you wake me up!?" because he failed Bridget and knew he'd be sleeping on the couch that night. Tony's running too fast because all he could think about was getting in Bridget's pants also led to Fievel nearly being devoured by roaches and captured by the cats.
In the dozens of times I watched this movie as a kid, I never noticed until now that Tony was really just a horny mouse who used Fievel to score points with some chick he picked up on the street. Then he had the gall to complain in the end when no one was thanking him. You didn't do sh*t, man! What a douche!