Gargouille was a member of a faction of Acolytes led by Exodus who participated in an assault on Wundagore Mountain in the European country of Transia, home of the enigmatic scientist known as the High Evolutionary. The Evolutionary had developed a powerful mutagenic compound known as Isotope-E, which the Acolytes coveted for themselves.
M-Day, Messiah Complex & Nation X
Gargouille retained her mutant powers after M-Day.
When the X-Men were looking for Exodus in order to find Sinister's Marauders he had recently joined, they assaulted the former Acolytes who had refused to follow him: Neophyte, Projector, Vindaloo and Gargouille. They were defeated and Projector then answer to Logan's question about Exodus' current location.
She was recently seen on the streets, homeless and beging for money. As everyone ignored her, she went back to her 'home' in the sewers, to see a companion or boyfriend of her. Once there a Predator X met her, and it is assumed that she died.