Mezmeron is the leader of the Ghost Monsters in the Pac-Man animated series. He appears a foreboding human in a red cloak with a mouth cover. He speaks through an electronic filter. His main goal is to defeat Pac-Man, seize the Power Pellet Forest and harness their energy to conquer Pac-Land.
Mezmeron seems to never want to do anything himself; his main role in the series is to give orders to the Ghost Monsters then verbally & physically abuse them when they fail or do something wrong, which happens a lot. Even though he's able bodied and quite powerful and resourceful, he's never really directly antagonized the Pac-People himself. He just keeps sending the Ghost Monsters out on one doomed to fail mission after another.
Nothing is known about his background or his motivations beyond his sole stated goal "I must have those Power Pellets!!!". He's never outright stated what he intends to do with them if he ever got them. There's really not much to the guy if you want to be honest.
It has been shown that Ghost Monsters are able to wear his cloak after being chomped by Pac-Man. Mezmeron has an entire closet full of identical cloaks in the same room where the Ghost Monsters extra skins are kept.