Regular Show: Birthday Gift/Cat Videos/Struck by Lightning/The Return of Party Horse

Rigby always gives Mordecai the worst birthday gifts, but this year it's going to be different. / Mordecai and Rigby have to get Benson to stop watching cat videos. / Muscle Man and High Five Ghost get struck by lightning and can't remember each other. / Mordecai and Rigby want to help their friend Party Horse get back together with his girlfriend.