Super Mario Galaxy -- Hatch a Baby, Immediately Kill Him
The Super Mario franchise follows the same logic as the Friday the 13th movies -- when things start getting stale, send your main character to space. The end result is so whimsical and fun that by the time you defeat Bowser for the 500th time you'll have completely forgotten that your amazing adventure kicked off with the brutal murder of the first boss. Meet Dino Piranha, who's not exactly the most threatening foe Mario has ever faced.
As a general rule, not having eyes places you at a disadvantage.
Those of you familiar with piranha plant physiology will note that he looks rather young. That's because when you encounter him he's peacefully incubating in his egg. At this point you and your violent plumber avatar slam into the egg at an incredible speed, cracking its delicate exterior.
If Peach wants a space omelet, she gets a damn space omelet.
With the shell still partially intact, the poor newborn stands upright and begins wandering around with his tail trailing behind him.
"Ah, the miracle of life. Well, time to beat the shit out of it."
Blind, aimless, and undoubtedly terrified of the sudden harsh reality that's just been thrust upon him, Dino gets his second trouncing when Mario knocks his tail into the sky. The elastic appendage comes careening back into the egg, shattering the only remaining barrier between the baby and the horrible outside world that, as far as he's concerned, means only to kill him in a painful and humiliating manner.