crest_worm
Insects seen in the Fate_series, which incubate in their host and grant them the ability to use magic at the cost of shortening their lifespan. Appeared extremely_phallic in the original release of Fate/stay night, but was edited for the Realta Nua release and anime adaptations.
Matou Kariya uses an evolved form of the crest worms, blade wing worms, in combat.
Aliases: none