Me too, but for a different reason.

Why no one say King K Rool? He literally looks like he's dead and then he gets up, after the credits roll

Silver the Hedgehog from Sonic 2006. If you can't relate, you should be thankful. He is, in my experience, the worst boss in the history of gaming, by the simple fact that the gameplay is seriously broken and it is nearly impossible to beat him your first time. Sega are the real trolls. Just look up a video of the gameplay (preferably Game Grumps, if you want the full jist of everything that goes on in your mind when you fight him) and you'll know what I mean.

"IT'S NO USE!"

Kintaro and Shao Kahn in Mortal Kombat II. I've been playing this game for years and still struggle to beat these two.

Any boss from a SNK fighting game. I think the designers thrived on a diet of nothing but the rage and tears of players trying to finish their fighters.

Blue from Pokémon. He's always one step ahead of you, bragging about how many Pokémon he's caught and how many badges he has. I had so much trouble beating the Elite Four, but I eventually succeeded, only to be told that piece of $%&* was still left to beat. And, yes, he did beat me on my first try. Blue is just an all round douchebag troll.

The ghosts in Pac Man. Why can't I eat them?

Any boss in an RPG that you're forced to fight and forced to lose to as part of story progression. Don't make me bother with a battle if it's designed to be an unbeatable waste of time.

That dude with the Machine gun in who you faced before your Brother at the end of Double Dragon was a bit of a troll.
But the ultimate troll in that game were those bloody square pillars that pushed out of those grey walls in the final stage that had NO pattern.