Filburt Shellbach is a character in Nickelodeon's animated series Rocko's Modern Life, the Netflix animated special Rocko's Modern Life: Static Cling and the comic book series of the same name. He is an anthropomorphic turtle who is often pessimistic. 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. Filburt Turtle. However, in the episode "High Five of Doom" Rocko and Heffer read in Filburt's diary that his full name is Filburt Shellbach, which was officially considered his real name. Mr. Lawrence provided Filburt's voice.