Professor Rupert Marmalade IV, actually named Kdjfloerhgcoinwerucgleirwfheklwjfhxalhw in the books, is the main antagonist of Aaron Blabey's book series The Bad Guys, as well as its DreamWorks' 2022 film adaptation of the same name.
He is an anthropomorphic guinea pig who is known for being a philanthropist and might seem like a good person, but in reality, he's a cruel, self-centered fraud who wants to destroy the world and steal anything by using others. He is also Mr. Wolf's former mentor-turned arch-nemesis.
He was voiced by Richard Ayoade in the film, who also played Mr. Pickles in The Boxtrolls and The Snowman in Danger Mouse.