When I was around level 10 on my hunter I happened to look into the canal in Stormwind. I saw a HUGE white crocodile sleeping just below the surface. He was such a high level I couldn't even see it. Naturally, like any curious noob, I thought he must give something amazing if we killed him. So I raised the alarm and soon we had a small group of really high level players attacking him.
I sat on the bridge shooting him, barely scratching his tough hide. He was a lot stronger than I expected and proceeded to kill off most of the other players and lots of the city guards. I was keeping a safe distance because I knew he would kill me if he so much as sneezed on me. But one by one, the warriors fell, and I was the only one left. So like any lowbie, I ran as fast as I could away from him, with a giant crocodile in hot pursuit.
I ran literally all over town, and everyone stopped to stare at this poor little elf running in terror from a giant croc. It chased me up and down the streets, refusing to leave me alone. It finally caught and killed me in the town square at the steps of the bank. He went back to his sewer and seemed pretty happy with himself. We all got back up, regrouped, got a bigger army, and finished him off finally. And the great treasure for killing him: A worthless chipped croc tooth. They gave it to me for soloing a lv 60 elite for a while at level 10. I wish I could have made a necklace out of it.