Filburt Shellbach is a fictional character, an anthropomorphic turtle, and the tritagonist of the animated television series Rocko's Modern Life and the comic book series of the same name.
Whenever Filburt feels uncomfortable or disturbed, he is known to say, "I'm nauseous! I'm nauseous!" He also occasionally says, "Oh, boy" and "Oh, fishsticks."
He was voiced by Doug Lawrence who also voiced Plankton from SpongeBob SquarePants, and Edward Platypus from Camp Lazlo.