Ellie Phimister was a Genoshan teenager and a student of Emma Frost's telepathy class. She experiences a vision of a massacre on Genosha shortly before Cassandra Nova's Wild Sentinels appear and kill her and 16 million people.[9] Frost survives due to her secondary mutation activating and transforming her into diamond, and retrieves Ellie's corpse.[10]
In Necrosha, Selene and Eli Bard temporarily resurrect Negasonic Teenage Warhead and other mutants using the Transmode Virus. Unlike other resurrected mutants, Ellie does not fall under Selene's control.[15] She is later apparently killed when the Black Queen absorbs the souls of Genosha's population.[16]
In Marvel Now!, Ellie appears alive, having begun a mundane life in Albuquerque. Deadpool and the Mercs for Money capture her at the behest of an organization called Umbral Dynamics, unaware that the group intends to siphon her power into the Presence.[17][18] After her rescue and the defeat of Presence, Negasonic Teenage Warhead adopts a new punk-inspired look and joins Domino's incarnation of the Mercs for Money alongside Hit-Monkey.[19][20]
Negasonic Teenage Warhead later inadvertently creates an alternate timeline where the conflict between the Inhumans and X-Men never ended. After Deadpool is mortally wounded, Negasonic travels back in time to avert the timeline.[21]
Negasonic is the only one of the Mercs to remain in Deadpool's employ after his defection to Hydra during Secret Empire and subsequent memory wipe after The Despicable Deadpool, helping him run a new business called "Deadpool, Gun/Swords for Hire".[22]
Ellie possesses superhuman strength, speed, durability and reflexes. She is able to overpower a host of skilled, military, or uniquely trained mercenaries in hand-to-hand combat, as well as showcasing superhuman physical prowess beyond the norm, battling the likes of Scorpia and Titania.[23] She can read the thoughts of others and project her own with her telepathic abilities.[9] She possesses precognitive abilities.[9][24] She is the only person aware that Proteus has possessed Destiny and she shows her precognitive abilities, announcing to Selene the imminent return of her victorious inner circle.[25] Ellie showcased a host of new abilities, creating a house and home for herself out of thin air with her thoughts. She has the ability to harness, generate, and absorb radioactive energy into herself, allowing her to achieve feats such as fabricating objects out of thin air like clothes or shelter and levitating people or objects with her mind.[20]
It is later revealed that Ellie's newfound power stems from an ability to manipulate reality at a quantum level. In an alternate dystopian future, Negasonic used her powers to alter the Terrigen Mist to make it harmless to mutants. Further exhibitions of her power include rearranging matter and energy into different shapes and forms at will, such as morphing Jack Chain's Darkforce binds into butterflies, changing Inferno's fire into flaming monkeys, mentally disassembling Domino's and Gorilla-Man's guns, and creating energy duplicates of herself at will.[26]
In 2017, Comic Book Resources (CBR) ranked Negasonic Teenage Warhead 15th in their "15 Most Important Women in Deadpool’s Life" list.[27]
In 2020, Scary Mommy included Negasonic Teenage Warhead in their "Looking For A Role Model? These 195+ Marvel Female Characters Are Truly Heroic" list.[28]
In 2022, The A.V. Club ranked Negasonic Teenage Warhead 99th in their "100 best Marvel characters" list.[29]
In 2022, CBR ranked Negasonic Teenage Warhead 8th in their "Gorr The God-Butcher And 9 Other Over-The-Top Names Comics Fans Love" list.[30]
Negasonic Teenage Warhead appears in Deadpool 2, portrayed again by Hildebrand.[34] She has become a full member of the X-Men and entered a relationship with Yukio.
^Cullen Bunn (w), Iban Coello (p), Iban Coello (i), Guru-eFX (col), VC's Joe Sabino (let), Jordan D. White (ed). Deadpool & the Mercs for Money, vol. 2, no. 1 (20 July 2016). United States: Marvel Comics.
^Cullen Bunn (w), Iban Coello (p), Iban Coello (i), Guru-eFX (col), VC's Joe Sabino (let), Jordan D. White (ed). Deadpool & the Mercs for Money, vol. 2, no. 4 (5 October 2016). United States: Marvel Comics.
^Deadpool & the Mercs for Money vol. 2 #5. Marvel Comics.
^ abDeadpool & the Mercs for Money vol. 2 #6. Marvel Comics.
^Deadpool & the Mercs for Money vol. 2 #7–8. Marvel Comics.
^Skottie Young (w), Nic Klein (p), Nic Klein (i), Nic Klein (col), Jeff Eckleberry (let), Jake Thomas (ed). "Back in Business" Deadpool, vol. 7, no. 1 (6 June 2018). United States: Marvel Comics.