As it happens, I changed my avatar to Marching Milde from Yoshi's Island without even reading this thread. Of course, Marching Milde is not an end boss, and there's nothing particularly great about Marching Milde, I don't even remember him/her/it....I just happened to make this drawing recently.
So I guess I need to come up with a new avatar! But it will have to be something delightfully obscure. So I'll have to draw it myself. I think I know who to choose...
Meanwhile, a few end bosses that I fondly remember:
- King K. Rool in Donkey Kong 64. Actually, all of the K. Rool battles are pretty cool, but the battle at the end of DK 64 was just really fun. Lots of humour, and they somehow worked every single Kong in the game into it.
- Whatever it was at the end of Axelay. With four different stages and about eight different kinds of projectiles, that boss was one tough son of a gun. Really intense.
- Mizar in Jet Force Gemini. possible choice for my avatar, but I still have an even more fiendish enemy in mind. Mizar was another real toughie.