Meta-humans

A meta-human is an individual who acquired superhuman abilities through a certain means. Most obtained their powers after surviving an explosion caused by a malfunction of the S.T.A.R. Labs particle accelerator on December 11, 2013. They were exposed to particles and dark matter that altered their genetic structure, or even atomic structure, giving them a variety of abilities. These abilities seem to often relate to what energy or matter they were directly in contact with at the time of exposure.

On Earth Two, rather than the particle accelerator exploding, Dr. Harrison Wells of that world allowed excess radiation to flow underground, with the first meta-human appearing 11 hours following.

Powers and abilities
There are a wide range of meta-human powers, including everything from time distortion to elemental manipulation. Meta-humans who gained their abilities from the dark matter explosion in Central City often have powers influenced by unusual conditions at the time of exposure: Barry Allen was struck by lightning and gained access to the Speed Force, giving off electricity when he runs at superhuman speeds, while Tony Woodward and Joseph Monteleone gained the power to transform into the substance they were immersed in during the explosion (steel and tar, respectively).

Due to their altered physiology certain meta-human powers affect meta-humans differently than normal humans. Barry remained infected by Bivolo when the effects only lasted 5 minutes in a normal person.

The emotional state of a meta-human also has an influence on their powers; reacting and strengthening when the meta-human is in a state of emotional stress.

Earth One meta-humans

 * Cisco Ramon/Vibe
 * Eobard Thawne/Reverse-Flash
 * Kyle Nimbus/The Mist
 * Firestorm
 * Jefferson "Jax" Jackson
 * Martin Stein
 * Nathan Bliss/Mr. Bliss(non-canon)
 * Joey Rose (non-canon)
 * Rajeet
 * "Hydro Hunter"
 * Roy Bivolo/Rainbow Raider
 * Shay Lamden/King Shark
 * Hartley Rathaway/Pied Piper
 * Shawna Baez/Peek-a-Boo
 * Mark Mardon/Weather Wizard
 * Meta spiders
 * Wangari Hollowell
 * Grodd
 * Jeremy Tell/Double Down
 * Henry Hewitt/Tokamak
 * Joseph Monteleone/Tar Pit
 * Adam Fells/Geomancer
 * Griffin Grey
 * Unnamed zoopathic woman (non-canon)

Deceased

 * Clyde Mardon
 * Danton Black/Multiplex
 * Bette Sans Souci/Plastique
 * Tony Woodward/Girder
 * Farooq Gibran/Blackout
 * Song/Black Star
 * Hannibal Bates/Everyman
 * Jake Simmons/Deathbolt
 * Ronnie Raymond/Firestorm
 * Russell Glosson/The Turtle
 * Valentina Vostok/Soviet Firestrom
 * Eliza Harmon/Trajectory

Former meta-humans

 * Barry Allen/The Flash

Earth Two meta-Humans

 * Shay Lamden/King Shark
 * Linda Park/Dr. Light
 * Caitlin Snow/Killer Frost
 * Hunter Zolomon/Zoom

Deceased

 * Deathstorm
 * Ronnie Raymond
 * Martin Stein (unwillingly)
 * Adam Fells/Geomancer
 * Cisco Ramon/Reverb
 * Al Rothstein/Atom-Smasher
 * Eddie Slick/Sand Demon

Behind the scenes

 * The term "meta-human" essentially refers to a powered human, hence the suffix. However, ironically, Grodd is one such meta-human that is not in fact human that still displays meta-human powers.
 * Valentina Vostok, Jake Simmons and Eliza Harmon are the only meta-humans that were not affected by the particle accelerator.