Zorom is the god of Life and Logic. Appearing as a corpse, he also speaks in riddles. According to the text in the Church of Necrogy, Zorom is waiting his puzzle to be complete.
He has the church of Necrogy. Praying to him can be useful as when you do, you heal to max HP and also get your max HP increased. But this also decreases your power. This can be useful on Nethack when you are using a class that doesn't use power. When you're wounded, and it's not good. Who you gonna call? Zorom.
Tips for fighting him at PentPlane are unknown for now.
When you kill Zorom you receive 50 heath pots