Killfith (キルフィス, Kirufisu) is one of the four possible Summon Beasts in Summon Night: Craft Sword Monogatari Hajimari no Ishi. He is a short, silent and sadistic demon hailing from the world of Sapureth. His primary magic is water.
From the outside, Killfith takes the appearance of a serious boy who never cares about anyone (much to the protagonist's chargin) but actually has a soft side, duely respecting Murno and eventually trusting the protagonist. He also pays respect to Wellman.
- Although Killfith is the protagonist's Craftknight partner, he is technically, in fact, Murno's Summon Beast.
- He is the only one of the four possible Summon Beasts who can fly in-battle (to do so, the player must make him jump and then pressing any key on the directional pad).
- When conversing with Eliez, Killfith claims he dislikes children