The Megagorgon is the Asphodel mini-boss and is a larger version of the regular Gorgon. It will spit out large numbers of homing petrifying projectiles, either one at a time or several in a wave formation. Getting hit will likely mean getting crushed by the Elite Skull-Crusher that appears alongside it. These projectiles can be deflected back at the Megagorgon, but it cannot be petrified by them.
'...The petrifying gorgons so were feared among the living, that the kings of men summoned the greatest of their heroes to dispatch them, claiming that the fickle gods desired it. The heroes somehow met with some success, and now, the Underworld is home to remnants of the gorgons' kind -- including a conspicuously larger specimen that dwells among remains of Cyclopes, each of their kinds, similarly spurned.'