Scooby-Doo! Mystery Incorporated S01 E04 Revenge of the Man Crab

"The most hauntedest place on Earth."

A Man Crab attacks Crystal Cove beach during a volleyball tournament for Trickell's Triquid diet mixture. The gang must stop him and solve this mystery before the tournament's female players, who the Man Crab has taken a liking to, are put in danger. Meanwhile, Velma gets some relationship advice from Daphne.