"The Really Bad Day!" is the ninth short to air as part of Oh Yeah! Cartoons, airing on December 8th, 2000.
Cosmo has to be bad for a day. Unfortunately, he's not very good at it, and ends up needed lessons in it.
Tropes that apply to this episode include:
- Beard of Evil: Cosmo grows one as part of his evil persona. So does Wanda at the end.
- Been There, Shaped History: Wanda was responsible for wiping out the dinosaurs during her last bad day.
- Circling Birdies: Timmy sees stars after Cosmo drops him at the beginning.
- Earth-Shattering Kaboom: Cosmo attempts one at the end.
- Here We Go Again!: Wanda grows a beard and says "My turn!" at the end.
- His Name Really Is "Barkeep": Jorgen Von Strangle reveals he has a dog named "Eat," who eats heads. He has another unnamed dog who "eats the rest" (of the body).
- Identical Grandson: Vicky's ancestor, Vicky Khan.
- Phlebotinum Killed the Dinosaurs: Wanda casually reveals she killed the dinosaurs as part of her bad day.
- Poke the Poodle: All of Cosmo's initial attempts at being bad.
- Voice Changeling: Timmy manages to perfectly disguise his voice while talking to Vicky on the phone.
