Vampire
Vampires, or vampyres, were a class of undead, supernatural beings. They exhibited a range of traits in various varieties across the Multiverse.
Nature
Powers and limitations
In at least one universe, it was possible to turn into a vampire over time after being bitten by a regular vampire, but this was not a given. These vampires needed human blood to survive, and did not drink any other beverages. (PROSE: Camera Shy) They were invisible in mirrors (PROSE: Camera Shy) They would gain a temporary bond with the person whose blood they'd drunk, allowing the vampire to sense their location. This had particularly spectacular effect when a vampire attempted to drink some of Jenny Everywhere's blood. (PROSE: The Absquatulation of Jenny Everywhere)
In that and other universes, vampires were weak to direct sunlight; in some circumstances, their skin began to burn after a few seconds of exposure, though they could quickly recover from this if taken back into shade. (PROSE: Parallax, COMIC: A Letter From Beyond) While “sleeping” in the daytime, vampires would go catatonic, becoming indistinguishable from freshly-dead cadavers. They could, if necessary, be forcibly awakened early by dripping some blood into their mouth. (PROSE: The Absquatulation of Jenny Everywhere)
In another universe, vampires needed human blood to survive, though a synthetic substitute existed, but they could walk in the sunlight unprotected with no visible ill effects. (COMIC: Infinity Apartment)
In Reality Z-25 31-H, vampires could feed non-lethally, drinking only a quarter of their victims' blood. They had other powers, including increased strength, speed and senses, and Marcus had wider-ranging magical abilities up to and including teleporting people out of his chosen domain with a touch, although this may have been atypical. (COMIC: Kate Five vs Symbiote - Chapter 2)
Physical traits
Many vampires had sharp canines, which were more properly referred to as fangs instead of teeth. (PROSE: Century Smith and the Time Terror, COMIC: Infinity Apartment, Jenny Everywhere in the House of Terror) Some had unusually-coloured eyes: Alan's were golden, (COMIC: Infinity Apartment) Marcus had normal whites but red irises, (COMIC: Kate Five vs Symbiote - Chapter 2) and the fake Dracula appearance once used by Strach had eyes with yellow “whites” and red irises. The latter also had pointy ears. (COMIC: Jenny Everywhere in the House of Terror) Ibdis had extremely pointy ears, as well as chalk-white skin (COMIC: A Letter From Beyond, PROSE: Meet the Undead, etc.) and clawed fingers. (COMIC: Simple Logic) Kim could temporarily develop clawed fingers as a defense mechanism when startled or otherwise made to go feral. (PROSE: The Absquatulation of Jenny Everywhere)
Association with bats
Some vampires, including victims of the Sanguivorian vampires and the vampires of the 819th Universe, could also turn into bats at will. (PROSE: Century Smith and the Time Terror) Kim, a friend of Jenny's who had vampiric abilities, though she never called herself a vampire, had the ability to turn into a swarm of bats, which would pool together to reform into a single woman when she took human form again. (PROSE: Camera Shy) Alan, a vampire from yet another universe, could grow bat-like wings on his back at will, adjust their size, or put them away entirely. (COMIC: Infinity Apartment)
Specific types
The Invisible Vampyres of Sanguivor were, as their name implied, invisible. They were beastly creatures who usually killed their victims. However, a non-lethal bite from them would result in the victim beginning to turn into a vampire themselves. They would have the ability to turn invisible too, but remain more human and intelligent than normal Sanguivorian vampires, as demonstrated by Acantha. (PROSE: Century Smith and the Time Terror)