Red Hare, Class Name Rider (ライダー), is a Rider-class Servant summoned by Ritsuka Fujimaru in the Lostbelts of Fate/Grand Order.

The horse of Lu Bu. It was said “Among men, Lü Bu; among horses, Red Hare” in terms of their prowess. The horse was not attached to anyone but Lü Bu, and it has been said that once Lü Bu managed to jump over a castle's trench of at the very least more than 30 meters while riding on it.

The Flying General Lu Bu, whose actions are told of in books and stories such as the Romance of the Three Kingdoms.

A legendary warrior and general boasting peerless courage, he is said to have continued to fight until the end of his life. With his favorite horse, Red Hare, he ran through the battlefield.

(Source: TYPE-MOON Wiki)