Undead Knights (アンデッドナイツ, Andeddo Naitsu) is an action-adventure video game developed by Team Tachyon[1] and Now Production and published by Tecmo for the PlayStation Portable.

The story follows three knights—Romulus Blood (Keith Ferguson), his younger brother Remus (Andrew Kashino), and Remus's wife Sylvia Gradis (Megan Hollingshead), princess of Cavalier—as they seek revenge against King Kirk Gladys (Steve Blum) and his wife Fatima (Wendy Braun) for slaughtering the House of Blood.

Romulus is a human knight and former head of the House of Blood who made a Faustian bargain with an invisible demon known as The Beast (Steve Blum).

The undead knights encounter genetically engineered soldiers called Ouroboros created by the mad, selfish wizard Lord Follis (Liam O'Brien).

After the battle, Fatima's younger brother, Jester (Thomas Brownhead), reveals Romulus inadvertently killed Sylvia and Remus in a rampage after they were captured by Kirk's knights.

In her last moments, Fatima offers a crystallized stone made of demon blood to protect the warriors from The Beast, fearing they would be hunted.

Some scorned the inconsistencies with the decorum of the genre and condemned the mixture of its heavy metal soundtrack[16] as well as its vulgar language incongruous with the game's fantasy medieval environment.