SpongeBob's girlfriend: Kappa - A cute turtle-like monster girl who lives near water and loves to play pranks. Patrick Star's girlfriend: Mermaid - A seductive monster girl who loves to lounge around in the ocean and is known for her beautiful singing voice. Squidward Tentacles' girlfriend: Medusa - A stunning monster girl with snakes for hair and a love for music and art. She is misunderstood by many but finds solace in Squidward's company.