1. Joker gets his hands on The Mask
In one of comics' oddest crossovers, The Joker finds himself in possession of the Mask of Loki. We're not talking about the smirking Marvel Loki either; instead, this artifact originated in a Dark Horse comic series and later inspired the horrifying Jim Carrey movie The Mask. Somehow, the mask in question just so happens to end up in a Gotham museum that Joker just so happens to be robbing. After discovering its powers, Joker puts it on, vomit-inducing yellow suit and all. Can you tell I have feelings about The Mask?
Commissioner Gordon brings in Lt. Mitch Kellaway from Edge City to help Gotham stop Big Head -- I mean, Joker. Batman fought him at the scene of the crime, when he first put on the stupid mask. And Joker basically destroyed him and his Batmobile. Batman is severely injured, but everyone actually thinks he's dead.
So while Batman is out of commission, Joker-as-Big Head starts this terrible television show with lots of awful jokes and plenty of destruction.
Harley Quinn is relegated to camera girl, and she's forced to follow after this nutcase's series of adventures through the streets -- which result in Gotham's police force shooting down the Joker with a massive tank. But given the cartoony invincibility powers inherent to The Mask, it obviously doesn't work. The Joker is being a big jerk to everyone, including Harley. As usual.
The Joker's Mask shenanigans last for a span of four issues -- too long, if you ask me -- before Batman finally makes it back into the story and convinces Joker that the Mask just isn't funny.
After sprouting another head, Joker just takes the Mask off. That's apparently all it takes? To close the series, Kellaway takes the Mask and brings it back to Edge City. He digs up Stanley Ipkiss' grave and throws the Mask in there with him. It gets reburied with his body, only to evoke thoughts of the worst horror movie ever: the Mask, but as a zombie.
2. That time that Deadpool teamed up with a vampire cow named Bessie
You probably already know Deadpool, but we should probably talk about the other half of this team-up. Uh, so, Bessie the vampire cow. How did she become a vampire? Easy! She started off as a regular ol' boring cow in Switzerland, but was drained of her blood by Dracula. Poor farmer Hans found Bessie and buried her, but she arose a few days later as a vampire. Now Hellcow, she flew to the United States. Namely, Cleveland, Ohio. Weirdly enough, Howard the Duck ended up "killing" her, but she rose once again in the Deadpool Team-Up.
Deadpool and Hellcow met while they were both in the captivity of the wacky, bad mad scientist Dr. Kilgore. He locked Hellcow in a cage and I assume milked her, because he drank her vampire cow milk in an attempt to stave off death. It didn't exactly work, so Dr. Kilgore captured Deadpool to learn about his healing abilities.
Dr. Kilgore casually takes out Deadpool's pituitary gland and injects pituitary gland-stuff into himself. It works, because he becomes really hard to beat, but he also now has cancer, and is generally quite mangled. Despite not speaking English -- she only says moo -- Hellcow seems to understand Deadpool.
She breaks out and together they beat the shit out of Dr. Kilgore. Sort of.
At least, they put up a good fight. Deadpool is ready to go out with Hellcow. He loves Hellcow... until she bites him, after which Deadpool temporarily becomes a vampire, too. Together, team Deadcow eats Dr. Kilgore, lights him on fire, and dumps acid on him. Dr. Kilgore melts, and Deadpool flushes him down the toilet.
Wade remarks: "Hellcow, I feel this battle, this victory has bonded us in a very deep and real way. Can you feel it too?" Together, they begin a new and beautiful friendship. Until they walk out into the sun, and Hellcow is sizzled down to a little hamburger patty.
Something about sun, right? Deadpool ends up going back into the comic and saving Hellcow, but it takes 60 tries. Bessie then flies away, probably slightly upset that Deadpool ate her before deciding to save her.