Chopper is a regular reindeer, except he had a blue nose so all the other reindeer on Drum Island ostracized him from their herd. Eventually, he accidentally ate a Devil Fruit that gave him the power to take human form and also the intellect of a human, but that only further isolated him from the rest of the reindeer and also the other humans who thought he was a monster. He met Doctor Hiriluk who took him in and raised him as a son without judging him for being neither fully human nor fully reindeer.