Last night my adventuring party was attacked by and elder earth elemental. It has reach and our Cleric moved forward to deliver a harm spell. He provoked an AoO for not casting defensively. (stupid, I know)And the Elemental hit him with two slam attacks. This caused a bit of an uproar about how it gets to attack twice with an AoO and my DM said that since the Bestiary entry only gives her the one MELEE line to go off of that's why it got both slams off. I tried looking for rules to clarify but didn't find any.
Was she right?
(the Cleric by the way was turned into red paste smeared on the cavern floor, which we then had to get raised. frickin hilarious)