Lord Fredrick, King of the Snowmads was the mastermind behind the takeover of Donkey Kong's island. You face him at the very end as he's obviously the final boss of the game.
You fight him in a volcano, which should oddly be a snow-beast's least favorite place to be.
While some previous battles change its scenery, the battle is pretty simple. But facing his brute strength and ice magic can be challenging. Let's just say, I got hit a lot.
But eventually he was a goner and the Kong family got their island back. Not the greatest final boss in Nintendo history, but I liked him overall.