Before the Visord showed up a Garganta opens up with Wonderweiss and a creature Gin calls Hooleer later on. seeing it Captain Komamura says that it was the same eye he saw when Aizen was estracted from the Soul Society by the Menos.
But what is Hooleer? it doesn't have a Hollow's Mask or any fragments of one nor does it have a hole on it's body (at least from what i have seen). is it even a Hollow?