The Great Mighty Poo is a character and boss in the game, Conker's Bad Fur Day.
Upon entering the giant mound of poo in the Windy section of the game, Conker is warned by a local that something "came out of the shite." Upon investigation, Conker is told to bring sweet corn to giant pool of wet poo in the middle of the room. After delivering the sweet corn, the Great Mighty Poo rises from the crap and begins his soprano, or as the game states it, "sloprano."
Despite being made of excrements, the Great Mighty Poo prefers to sing opera and devour sweet corn. However, upon beginning his opera, the Great Mighty Poo opens his mouth, a dangerous move as Conker can then bombard him with toilet paper. He's eventually defeated after his singing breaks the glass to the flusher, where after activation, the Great Mighty Poo is literally flushed.
The Great Mighty Poo has become one of the game's most memorable characters and boss fights, mostly in part to the character's "Great Mighty Poo Song."
The Great Mighty Poo Song
I am the Great Mighty Poo
And I'm going to throw my shit at you
A huge supply of tish
Comes from my chocolate starfish
How about some scat you little twat?
Do you really thing you'll survive in here?
You don't seem to know which creek you're in
Sweet corn is the only thing
That makes it through my rear
How d'you think I keep the lovely grin?
Now I'm really getting rather mad
You're like a niggly tickly shitty little tag nut
When I've knocked you out with all my bab
I'm going to take your head
and ram it up my butt (Your butt?)
My butt (Your butt?)
Thats right my butt (Errr...)
My butt (Errr...)