There are two types of existing beelzebub:
The blue: These are beelzebubs in the form of a gigantic fly.
The green: These are beelzebubs in the form of a gigantic mantis. Normally they are slow but when they attack they are quick.
This evil spirit inhabits the body of a fly. There hideousness is not to difficult to imagine from its apearance and movement.
What appear to be maggots that the blue beelzebub vomits are not real maggots. They are a form of evil power that when in contact with it, will prevent your weapon from firing so switch to a sword.
The large green beelzebubs serve like a evil power bank for the blue air borne beelzbubs. They seem so be stronger since they have larger physical mass. The green beelzbubs eat the dead to gain more power and become even stronger.