Phalange: a large skeletal construct prone to random outbursts of dancing, the incessant chatter of the phalange causes temporary insanity in those who hear it. The clawed tongue is the creature's true mouth. It stretches to great lengths to tear flesh from confused opponents.
Malphas: according to legend, the first of these monsters were patterned after the hounds of the reaper himself. They are blind, but their sense of smell and hearing remains unmatched. They are extremely fast and seem to enjoy killing for killing's sake. Feral Malphas hunt only in pairs.
Abigor: a small and timid undead construct, but one with powerful psionic capabilities. It cannot speak, but possesses great intellect and is fascinated by books. Some Abigor are known to create and command monsters of their own.
Gromory: humanoid, reasonably intelligent and quite strong, Gromories are one of the oldest, most basic of undead creations and remain in widespread use, considered a reliable and versatile "classic".
Plazm: these gelatinous creatures are well known for their regenerative abilities, and can continue to function even if broken into pieces. Their semifluid flesh even has restorative effects on other creatures, and they happily mend the wounds of their allies...if they can be convinced not to digest them.
Vornet: this venomous predator is a fusion of human and insect best known for its fearsome temper. It dies after one use of its potent sting, making it the envy of those on the receiving end. Its insect half drives it toward flowers, but it no longer knows what to do with them and will usually just end up happily rolling in them, rather like a domestic dog.
I love them all, i can't pick which has been best upgraded.