Filburt Shellbach is a main and supporting character of the cartoon Rocko's Modern Life and the comic book series of the same name. In the Australian website of the television show, his name is sometimes spelled as Filbert and sometimes as Filburt. In the comic book, his name is spelled Filbert. On the show's creator Joe Murray's website and in the episodes "Born to Spawn" and "Uniform Behavior", his name is spelled as Filburt. In the episodes "Born to Spawn" and "Fortune Cookie", he is referred to as Mr. Filbert Turtle. However, in the episode "High Five of Doom" Rocko and Heffer read in Filburt's diary that his full name is Filburt Shellbach. Doug Lawrence provided Filburt's voice. 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 also popularized the phrase "Turn the page, wash your hands." Filburt becomes age 21 in the episode "Born to Spawn".