Masks
Mask: The Mask is a spirit that wanders through the Pyramid aimlessly. They seem to be aware of Pyre, and stare at him, but stay on their path without chasing him.
Mask of Ashes: The Mask of Ashes has stronger ties into the world than the normal Mask, making it harder to banish.
Mask of Flames: The Mask of Flames has even stronger ties, making it harder to banish and giving it the ability to throw Hellfire.
Demons
Imp: The Imp is a lowly demon with nothing to lose, and it chases Pyre relentlessy.
Foliot: The Foliot is a higher ranking demon that stays back and hurls Hellfire from afar.
Djinni: The Djinni is a spellcaster with a variety of Hellfire-based attacks to hurl at you.
Marid: The Marid is a huge beast, making it hard for it to fit through most halls of the Pyramid, but if it does reach Pyre...chomp!
Undead
Zombie: The Zombie hides underground until Pyre comes near, then rises and starts to chase him.
Ghost: The Ghost is a spirit caught between Heaven and Hell, and it will chase Pyre even through walls.
Skeleton: The Skeleton is a mass of bones that will tear Pyre apart if it can reach him.
Vampire: The Vampire is a beast that can replenish it's health by taking it from Pyre.
Animations
Golem: A mass of moving stones that can only sense Pyre when he walks.
Gargoyle: A blind beast that uses echolocation to find Pyre.
Mutants
Giant Spider: A mutated freak that will leave webs around for Pyre to get stuck in.
Monster Ivy: A plant that will strike if Pyre gets near.