Gryphon looks tough to kill considering it's an AST with i170 gear. He doesnt seem to be seriously killing but he's thrown enough at it to have killed it, had it been an ARR mob.

On the other hand, the gryphon seems to be having trouble killing the AST too. Maybe it does hit harder, considering ARR open mobs hit for like 1% with their auto attacks but harder to tell since there's no UI to look at.