"Undead" is a term which refers to any creature which is deceased, yet acts as though it is alive. Below are listed some of the undead which appear in Pandora comics.
Vampires are highly magical undead who prey on humans and drink their blood to sustain both life and power. While vampires are easily the most powerful undead, they also have the greatest weaknesses. Vampires are subject to Fairy restrictions, even if they were not fae to begin with. Direct sunlight kills them almost instantly. They cast no reflection and can therefore be easily identified in the presence of a mirror. They cannot abide garlic and many are obsessed with counting.
A vampiel is the offspring of a vampire and a living person. Vampiels possess only part of the power of a vampire, with none of the weaknesses.
A ghoul is a living person who has been enslaved by a vampire. Ghouls begin as living, and if released from the vampire's control, will return to normal. If, however, the ghoul is killed, it will continue its service as an undead, and once its vampire is destroyed, the ghoul, also, will be destroyed.
A flesh golem is a reanimated corpse, often constructed of bits of other corpses. Examples include Frankenstein's Monster and captain Poland.
Mummies are animated by external power for a purpose, usually to act as guardians of some important tomb or treasure. Pandora's favorite mummy is Kitty Hotep.
In real life, a zombie is a person who has been carefully drugged until they appear dead. The person is buried alive and later dug up by a zombie master who then puts the zombie on hypnotic drugs to keep them compliant. Zombies who are taken off of the drugs become normal living people once again.
The classic definition of zombie is a creature who is completely dead but psionically animated by external magic. It is also a generic term for any undead.
Wights are like zombies, but the power which animates them is internal, deriving its energy from spite.
A skeleton is a zombie or wight whose decay is so advanced that only bones are left. In Homonymia, some skeletons exist who were never alive, but constructed as skeletons.
Peculiar to the Intense Universe, Aqade are psionically powerful undead whose abilities rival those of vampires. Unlike vampires, however, Aqade work in groups, amplifying one another's powers. In their true form, Aqade appear as humanoids with slimy, spongy, puss-covered skin. Their noses are like syringes and may be removed and used as a weapon. Anyone pierced with this weapon is converted into an aqade. The chief weakness of the aqade is mirrors. Any aqade who looks into a mirror will be caught in a psychic feedback loop which will rapidly result in his spontaneous combustion.
A lich is a mage who has died and continued on, powered by his own magic.