For your edification--A simple glossary of creatures, agencies, and terminology for Infinity Earth.  You'll have to browse farther to find stuff on Infinity: Prime and Infinity: Empire..

Creatures

• Abyssians: Huge, powerful, bat-winged creatures created by the dark immortal Hades to serve as elite soldiers.

• Creepers: Strange, light-sensitive, barely physical servants of the immortals' "Enemy."

• Dragons:  Monstrous, reptilian creatures created by Loki when the immortals first arrived on Earth Prime.

• Fey: Mysterious non-human entities.

• Goblins:  Human children twisted beyond recognition by dark magic and genetic engineering to serve as Hades' shock troops.

• Hybrids: Anthropomorphic human-animal mixes used by the "Enemy" as soldiers.

• Immortals:  Once worshipped as Gods, these powerful beings walk the earth in the guise of mortal men and women. 

• Lycanthropes: Infected by a mutated form of the vampire virus, these creatures shift shape not with the phases of the moon, but in times of great emotional stress or through an effort of will.

• Mages: Humans infected by a metavirus that reverses the genetic damage done by the "Enemy" in preparation for their intended invasion.

• Metahumans: Altered by one of Loki's metaviruses, metas are this world's equivalent to super-heroes and, conceivably, super-villains.

• Metapsi:  A person who gains increased psychic abilities upon becoming a Metahuman.

• Parahumans: Enhanced humans.  Faster, stronger, tougher, and (sometimes) smarter.

• Psi:  A person with psychic abilities.

• Spirits: Creatures created out of mana and given a semblance of life by the will of a mage.

• Trolls:  Humans who are twisted by a metavirus into a creature of monstrous appearance.

• Vampires: Blood-drinking, immortal creatures created by Loki entirely by accident.

Agencies

• P.A.C. Paranormal Affairs Commission:  A section of the Department of Homeland Security devoted to the investigation, pursuit, and apprehension of paranormal creatures.

• M.A.D. Magical Activities Division:  Also known as the "Mad Squad."  A sub-division of the P.A.C. devoted to issues involving magic.

• P.A.R.D. Preternatural Action Response Division:  "Monsters hunting Monsters."

• L.E.O.P.A.R.D.  Law Enforcement Officer, Preternatural Action Response Division..

• The Crimson Sash, Mirage, and Hex: Metahuman vigilante organizations.

Terminology:

• Magesight.  A slightly different way of seeing that enables a mage to see mana.

• Mana:  Energy left over from the creation of new universes or energy that yet hasn't gathered enough potency to form a new universe.  Also known as a "Probability Strand."

• Mana Effect:  A single magical effect caused by a mage by using a single mana strand.

• Power:  A paranormal talent possessed by immortals, Metahumans, vampires, or Fey.

• Spell:  A woven pattern of mana capable of generating multiple effects.