My most hated monter from anything has to be that bleeding pocket monster from Pokemon Pikachu(Die, Die, Die pikachu).

Vampires! Although I enjoy killing them when I can :D !

You didn't have a ribbon in FF8 lifetime that was FF7. I've met a more annoying enemy than a Demilich, or a blood soul. In FFX there's a monster called Earth Eater. Luckily it's only available in the battle arena. It's impossible to beat. It attacks twice per round, and does instant death. (If you're immune to instant death it does about 20,000 damage.)
Let's not even talk about the special Behemoth that has permanent armor, (Armor shaves off 4/5 of the physical damage.) does a 20,000 damage attack called popfly, and has final attack ultima. A 10,000 damage ultima! I killed that one though, and survived too. ;) A tip to those who get FFX stay the heck away from the battle arena! [img]smile.gif[/img]

Two Words 1.Insane 2.Halflings

Kobolds. I don't hate them, but many of my players sure do. Nothing humbles a high level character like some kobolds with a few traps killing them all.

Ruby Weapon from ff7 is my alltime most hated boss-level enemy. I dont care what any strategy manual said, I could not beat that stupid thing.

Illithids are the most unbalanced and hated re-occuring enemy Ive faced. Doest matter if your party is killing dragons in their sleep. A pack of these things just tears through your party.

Chev

ORCS!! i hate orcs!!!!

I really hated The Ilhitids and Beholders. Basically, I hate every monsters that can kill your characters in a way that remove them from your party. (As is getting petrified or getting your brain eaten)