Funny fictitious game bosses

Mega Man
Imagine a game like Mega Man. The hero and boss have energy bars, and fight in a small, non-scrolling room with a few platforms. The hero can jump and shoot a little pellet gun, and the boss can jump around too.

The game's premise is that you were teleported to an alternate reality where 80's and 90's music groups that have become "possessed" and must be defeated in order to cure them.

MC Hammer
(original: Funny idea for a NES game boss, 2011-02-28)

(copyright / trademark issues ignored) The hero drops into the room... and the boss is MC Hammer (complete w/ sparkly gold parachute pants). The background music starts playing "U Can't Touch This". He jumps around to the beat. When the lyrics would say "Can't touch this", if the hero is near him he takes extra damage. (Think Shredder's "flame" in Turtles in Time for Super NES.) When the lyrics would say "stop. hammer time" time for the hero freezes (he's suspended in mid-air if he's mid-jump). When time stops, MC Hammer starts throwing hammers at the player (purely horz in the player direction). The only way to avoid that attack, reminiscent of Dio's "The World"+knife combo from JoJo's Bizarre Adventure, is to time your jump so that you're out of the line of fire when time freezes.

Just when the hero defeats MC Hammer, Vanilla Ice drops down from a hole in the ceiling. His weapon can freeze you in place on contact (think Metroid ice-beam).

Other recording artists
Don't even want to know what happens when Tone Loc shows up. Maybe he steals $50 every time the hero gets hit.

The Bangles will attack with the "Eternal Flame". etc....

idk why I thought of this. The radio was advertising that this year's state fair headline group would be MC Hammer and Tone Loc.

Marvel crossovers
Despite the Marvel vs. Capcom fighting games and the Something Man naming scheme of Robot Masters in 8-bit Mega Man games, you're not likely to see Spider-Man or Iron Man at the end of a level in the next fake 8-bit Mega Man game.