Human souls who were either terribly evil, neglected when died and were not sent to Soul Society, or souls who have stayed behind and became one. Of course, souls are what they WERE. What they are now is a great monster with a white mask, different for each one who is ever hungry and will never stop questing its food, souls. They very in shape.
You need to start as this if you want to be an Arrancar, for you need permission to be an Arrancar. However you can be a Menos Grande.
Classes:
Normal Hollow: A strange shape and a thought only for food and killing.
Gillian: A huge hollow that is the mix of thousands of other Hollows that have began to eat other hollows, without a mind of its own.
Adjuches: A hollow that in Gillian stage has its own conscience and then takes control of the large body of hollows and changes into a smaller sometimes abstract shape, it has a complete mind of its own now and gains the strength of all the other hollows in the Gillian. The earliest stage that you will be allowed to be an Arrancar.
Vasto Lorde: No info known at the time.
Vaso Lorde you need to have permission to be.
Powers:
Eating Souls: Can absorb souls and eat them to grow, must kill Shinigami before you can take their souls.
Retreat: Open up a hole to Hueco Mundo, where no one can follow.
Unique: Most Hollows have their own abilities, you are free to create several abilities to match your person.
Cero: A red energy blast that can be fired from multiple points of the body.
