Neptune is the King of the Sea. He first appeared when SpongeBob pulled out a legendary spatula from a pile of grease. Neptune invited SpongeBob to come to Atlantis where he could live as a god, but SpongeBob rejected the opportunity. He later appears in the movie with his daughter Mindy, and his crown is stolen by Plankton, later ending up hypnotized by him. Eventually, SpongeBob returned Neptune's crown, and Plankton was defeated.
In the TV series, John O'Hurley provides Neptune's voice. Kevin Michael Richardson dubbed the voice of the live-action Neptune in the episode SpongeBob's House Party. In the movie, Jeffrey Tambor voiced Neptune.