For me, it was a spider from Duskwood. Freaked me out. I was running away because I acidentally pulled too many of the gnolls....across the river to safety....yay!...or so I thought....lol
My other memory was trying to solo some mobs in SFK as a Pally (it was impossible to get groups on my server), when trying to get a piece for Verigan's fist. I would pull 2 mobs, kill 1, run out of instance. Rinse and repeat the whole way....lol.