I love that fast reaction. "Holy crap this guy is a monster! Will you help us?"
So the first one was mindless gluttony.
This one is intelligent wrath or greed, maybe?
@Liquidxlax
It could just be an innate ability. This series does seem to be based on Monster Hunter. Several monsters in that series have innate skills that make them formiddable aside from their actual combat prowess.
Look at Zorah Magdaros, for instance. It never actually even attacks you. Just the random occurences from its existence and movement kills you in that 'fight'. Before Nergigante shows up to the fight, anyways.