The last boss in "Legend of the Mystical Ninja", although that's not an RPG.
Ultros sucks too. You know, the purple squid from FFVI. He was as hard as promised, but everybody loved him, and he was a pain in the ass. I wish I WERE a character from FFVI (EVEN GAU! I WOULD EVEN TAKE CECIL!) just to kick his ass for real. And I don't care how much times Kefka throws me some 500 lvl. mega-lightning-bolt. At least Kefka is COOL.