Dr. Heinz Doofenshmirtz has created the "Evil-Gathering-inator", which summons villains from different worlds to take control of worlds together. Heroes such as Perry the Platypus (Agent P), Randy Cunningham, Dipper Pines and Mabel Pines, Wander andSylvia join forces to stop the villains and save their worlds.
It later turns out that the villains grouped together to save their worlds from the evil dream demon Bill Cipher, who has threatened all of reality with his powers and is held prisoner by the villains; and the heroes' fight against the villains has only freed Cipher from his dimensional cell, as he now plans to take over their worlds. Realizing their horrible mistake, the heroes go on to defeat Cipher, who then disappears away in anger and defeat, allowing both the heroes and villains to return back to their worlds
- Gideon Gleeful's Gremloblin
- Lord Hater's Ship
- Hannibal McFist
- Dr. Heinz Doofenshmirtz's Norm Bot Inator
- Bill Cipher