In the movie, Louie is seen pushing his hot dog cart in New York City; trying to sell his hot dogs to hungry people. He smokes a cigar as he is waiting for a potential customer. A cat named Oliver smells Louie's sausages and goes up to the cart; hoping to get something to eat but Louie shoos him away instead. Oliver tries to go back and begs Louie to give him a hot dog by hanging onto his leg but this time, Louie kicks Oliver away into a pile of trash where a dog named Dodger has been watching the whole thing. Dodger offers to help Oliver get the hot dogs by pretending to scare the cat, thus causing Oliver to run and jump onto Louie frighteningly, as a distraction, while Dodger steals the sausages. As Oliver jumps off of Louie, he accidentally squirts mustard in Louie's face to which Louie throws the mustard back at him but misses. Louie doesn't appear throughout the rest of the film after this.
Louie pushing his cart
"Hey, it's a beautiful day, eh? Come on, folks. Step right up."
Unlike the other people in the film, Louie is the only human character seen in the movie with only four fingers instead of five.
Louie and Sykes share a few common things: they're both antagonists, they have the same enemies (Oliver and Dodger), they smoke cigars, and they have big strong muscles.
While Louie is antagonistic towards Oliver the kitten, Dodger the dog refers Louie to Oliver as "a well-known enemy of the four-legged world", implying that Louie hates dogs too.
Louie is perhaps the closest counterpart the film has to Mr. Bumble, the parish official who is incensed when the title character asks for more gruel in Oliver Twist, the Victorian novel that inspired the film.