Brownie Finn was a graduate of the American Victory Commission's Adorability Initiative. He was Jefferson Reid's teen sidekick in the first episode of Jefferson Reid, Ace American, but was captured by German mad scientist Vitas Brunholdt and turned into a mindless, ape-like monster. Jefferson helped him regain his mind by reminding him about all things American, and shortly thereafter he sacrificed himself in order to keep Jefferson from death.
Brownie was given a proper burial in America but later his grave was found dug up. General Rex Flagwell sent Jefferson and Abby Adams back to Brunholdt's castle to investigate. Brownie quickly captured and chained up Abby and Jefferson, and explained that after his resurrection at the hands of the Germans, he and Brunholdt became good friends and he's now turned Kraut.
Brownie nearly kills Jefferson and Abby at Brunholdt's orders, but they are saved by new teen sidekick Lucky Appleseed. When Lucky is killed by shrapnel, he sees Brownie's father calling him to heaven, who has Lucky relay the message to Brownie that his son's no Kraut. This snaps Brownie out of his brainwashing, and he releases Jefferson and Abby and is about to kill Brunholdt when Flagwell arrives and instead recruits Brunholdt to do science for America.
Brownie survived this encounter, making him the only teen sidekick still left standing at the end of an episode, even if he is technically undead.