I'd like to try and ID what he/she/it is, first.
Know (Arcana)
Rolled 1d20+10 : 19 + 10, total 29
Know (Religion)
Rolled 1d20+9 : 19 + 9, total 28
If it's not covered by those, he probably wouldn't know (those are the only two he has ranks in).
And... ah hell, whatever he is, I still need to kill him, sooner or later... so here is the AoO:
Attack:
Rolled 1d20+13 : 16 + 13, total 29
Damage:
Rolled 1d4+9 : 4 + 9, total 13