Your nightmare characters?

BigChief : When I was playing against Jinpachi just yesterday I realised 2 things:
1) His ridiculous stun attack (stomps the ground, you're stunned for at least 5 seconds), can be blocked low, and you will recieve a very minor stun.
2) He has Yoshi's d/f+4! Damn foo', how dare you!

I hated fighting him. Stupid sturns and that fireball attack. Grrr. He got on my nerves.