Pizza Head is the name for a supporting character in Baman Piderman.
Pizza Head is a friend of the Basement Monsters and serves as a portal to "da trees", where Tuba's Dad lives and the Squibs (Squib and Red Squib) lived. The portal is inside its mouth, and is created when it opens it widely. It can't or doesn't talk (at least until now).
When it first appeared, Those Guys were always feeding it with cookie pies and hiding it from the others. Until Happy Winter Friends 1 and 2, where it provides as a portal to "da journey" for Baman and Piderman. Sometimes Tuba uses its portal to visit her dad. It seems to be worried about who goes through itself, as initially it didn't allow Red Squib to enter Piderman's house. It also didn't let Pumkin try to save Squib from Red Squib, probably so he wouldn't be hurt. It also seems to be related with Tuba's Dad, as it helped him kidnap Baman, but the reasons of the kidnap is still unknown. It last appears in Paint Da House when it is sick and Baman and Piderman take care of it.
It appears genderless. However, in a Facebook comment where someone complains about their being no female characters in a picture on the Baman Piderman fan page thus making the picture sexist, a reply was given from the page itself saying, "Pssh, what about the squib and Pizza?" stating that the Pizza is a girl. But when questioned by another fan, the page said that the gender of the Pizza is a mystery, so the gender of the Pizza is still undecided, as of now.