Nuttiest Boss Battles?

This topic is for the discussion of boss characters that either have wacky moves, require weird strategies in order to beat, a ridiculous appearance or just plain side-splitting funny that you can barely concentrate when you fight them.

Although I haven't played it yet, the appearance and the attacks of those "Blockio Bros." in Mario and Luigi 3 just cracked me up! ;D

The Brobot's appearance sequence is pretty good for a brief laugh and it was pretty silly firing missiles from it nose and flinging 'Stache Boomerangs.
The Wooden Dresser boss from Dynamite Headdy is quite wacky.
First of all, its just a basic brown coloured doll, then I bounces offscreen and re-appears wearing a Dragon costume, eventually this changes into a Ballet Costume and dances everywhere and spins after you, and finally into a robot suit.

The entire game is actually full of wacky stuff like this.
The Final mini-boss of Aero Fighters 2:


He returns in Aero Fighters 3, where he rides a ghost and attacks by playing Banjo.
Yep, its quite a long climb, and you climb it after you defeat The Fury I believe.
I know a wacky-long battle. It's the final boss in Problem Sl- Wait, that's not a real game at all, or even a comic as it claims to be.