Sandy is practicing karate with a rather muscular fish. Sandy shows off her various skills while taunting the fish, and then tells the fish to demonstrate what he learned. He then lifts his arm and leg, and loses balance, which results in the fish landing on Sandy. Sandy then pops out and mentions, "This is much more fun with SpongeBob."
This is one of the four shorts that centered around an alternate universe where SpongeBob was gone.
This short was made to lead up to the premiere of WhoBob WhatPants.
"The muscular fish" was able to survive without a water helmet.