David Hasselhoff is a fictional character who appeared as a cameo in The SpongeBob SquarePants Movie. He is based on the real-life actor, singer, producer, and businessman of the same name
He was portrayed by his real-life counterpart, who also portrayed Nick Fury in Nick Fury: Agent of S.H.I.E.L.D.
He only appeared in The SpongeBob SquarePants Movie. While at the beach, he noticed SpongeBob and Patrick, who were stranded there and wanted to get back home. So, he offered his help, much to their excitement.
However, as they are proceeding, Dennis reappears and attempts to attack the marine duo. SpongeBob and Patrick fight him on the actor's back and legs. Hasselhoff's butt got stabbed by Dennis, but he did not feel much pain, although he did ask SpongeBob and Patrick to take it easy back there.
Hasselhoff subsequently manages to return SpongeBob and Patrick to Bikini Bottom and relaxes afterwards. At the end of the movie, he gets burnt by King Neptune.
It seems that this version of Hasselhoff is part cyborg or android, given his speed and the fact that he used his chest to launch SpongeBob and Patrick back to Bikini Bottom once they were above it after he had started standing on water.
His real life counterpart was born on July 17, 1952, meaning that he is 67 years old by now. However, since the movie is really set on March 14, 2004, he is 51 in the movie.