there is a mob in uldum calld myzerian Myzerian - NPC - World of Warcraft and you wont be able to kill this dragonoid
she has 387450 hp BUT fully heals to that point every 5 seconds which means
if you can take her down to 1 hp consistnetly, then your dps is above 77490 but if not you need a dps mod like recount or skada