Old Bluelip is supposedly a giant, deadly blue lipped clam and the main antagonist appearing only in the episode "Clams." He is known for stealing Mr. Krabs' Millionth Dollar. He gave back the dollar only to take the rest of Mr. Krabs' body.
Old Bluelip looks similar to all of the other clams in series. He is giant, light purple clam with blue lips and a large, pink tongue.
He only appeared in "Clams." SpongeBob, Squidward, and Mr. Krabs were fishing for clams when SpongeBob accidently ripped Mr. Krabs' Millionth Dollar off of Mr. Krabs' pants and throws it in the water. Old Bluelip then tries to swallow the dollar, but SpongeBob manages to reel it in. However, he jumped up and took the dollar out of Mr. Krabs' hand. He appears again at the end of the episode when Mr. Krabs jumps in his mouth to get the dollar. However, Old Bluelip takes Mr. Krabs, and SpongeBob and Squidward thought that he got eaten. But it actually turns out that only the lower part of Mr. Krabs' body got eaten so he could get the dollar back.
This character, along with the whole episode, is a reference to the Great White Sharks in the Jaws franchise.