Fairy Leviathan, known in Japanese as “Youshou” Leviathan, or simply Leviathan, is a member of the Four Guardians in the Mega Man Zero series. She serves as a secondary antagonist in the first two games, and is briefly a supporting character in Mega Man Zero 3.
Leviathan was created from X’s DNA data to aid humans resettling the Earth after the destruction of the Elf Wars. She is a military general of Neo Arcadia, commanding the Deep Sea Squadron. She wields a spear called Frost Javelin.
Leviathan lives on through Biometal Model L in the Mega Man ZX series.