Mantis' Hymn

Mantis' Hymn is a recurring song from the Metal Gear Solid franchise, and is the main theme of FOXHOUND member Psycho Mantis (and in the case of Metal Gear Solid 4: Guns of the Patriots, Screaming Mantis). It is a dark, somewhat repetitive song with chorus hums, meant to emphasize the ominous presence of the FOXHOUND Psychic, Psycho Mantis. Although the song is mainly used out-of-universe, it was given one acknowledgement in-universe, when Meryl is brainwashed by Psycho Mantis via his psychic abilities.

It first appeared in Metal Gear Solid, playing when Snake first encounters Mantis. It later reappears in The Twin Snakes, a remake of the former game, although it is remixed somewhat, also giving rumbling sounds reminiscient of thunder, and also having a slight shriek before the characteristic chorus chant.

In Metal Gear Solid 4, it reappeared again, both in its original format (played when Psycho Mantis appears in spectral form, with some hints to the remixed version from The Twin Snakes as Mantis is being banished to the spirit realm by The Sorrow), and in a remixed format where a female chorus is humming the characteristic vocalizations (as well as a slight shriek after the first stanza mirroring a wraith), and also having a more fast-paced version, which is played during Screaming Mantis's first appearance and during the fight with her, respectively, as a callback to Psycho Mantis. The Metal Gear Solid 4 version of the song was also playable as an optional track in Metal Gear Online.