If you didn’t get it from the lengthy song that talks about what a jerk he is, the Grinch is (was?) not someone you want hanging around when it’s Christmas time. So when he snuck into the Salty Dog Jiu-Jitsu Academy undetected, John Salter and his team needed a hero to step in and save Christmas.
As for who that hero was? Well, see for yourself. You’ll never know which celebrity will take up jiu-jitsu next!