Napoleon is one of the bugs from the Bug Trio from "Doof 101". He is also proven himself to the most intelligent of the bugs.
Like the rest of the bugs, Napoleon lives in Danville High School. He is first seen with Wendell and Floyd spotting Heinz Doofenshmirtz giving his genetics lecture to the students. It was Napoleon who came up with the idea of having himself and his friends to become the first insects to communicate with humans. To do so, they would have to do climb up to the table and hoist up a banner to greet the humans. Despite several difficulties, the bugs manage to make to the top of the table, but Napoleon is annoyed that Wendell and Floyd have misspelled their banner. As Napoleon berates the two for their stupidity, the bugs are then accidentally squashed by Doofenshmirtz's Evil Science 101 book, just as Doofenshmritz finishes lecture to the students before the bell rings. After Doofenshmirtz leaves with his daughter Vanessa, the bugs are revealed to have survived the book squash, though Napoleon states that he has broken his exoskeleton. ("Doof 101")
Napoleon and his friends later try to apply to O.W.C.A. in person after their paper applications are lost among New Year's party confetti, hoping to become O.W.C.A.'s first insect agents. Although inadvertently helping O.W.C.A.'s new agents defeat the infamous Professor Parenthesis, Napoloen and his friends fail to be noticed and are last seen at the site of an impressive explosion. He survives. ("O.W.C.A. Files")