"The Brain of Evil" is the eighth episode in Season 8 (and two hundred and twenty-fifth overall) of Regular Show. It aired on October 3, 2016.
Mordecai and Rigby accidentally release an evil brain.
Pop referrnces: The store where they find the brain may be a reference to the store of the movie "Gremlins" of 1984.
connections: One of the screens with images of cameras of security appears the Pops sleeping with objects flying around him, as in "The Dream Warrior". Pops continues with powers.