Master Necky is an enormous Necky who rules the clan of Neckys, who first appeared in Donkey Kong Country in Monkey Mines. He also later appeared in the Game Boy Advance port as a secondary boss in Chimp Caverns.
Would you believe I felt sorry for this guy when I watched him fall? I wasn't playing the game, I was watching my brother play it, but still.
All he is is a neck and a head Did you ever have one of those toys that's like a flamingo (or some animal) head on the end of a long stick, and you can pinch or grab things with it? Maybe that's what he is...