For the beta animal, see Horse (animal).
Horse is an unseen character in The Lost and Damned.
Background
Horse was a resident of Liberty City and a member of The Lost MC. Some time before the events of The Lost and Damned, Horse turned states evidence against the gang. He was, however, killed by some hitmen of the gang before he could testify.
Events of The Lost and Damned
During the mission "This Shit's Cursed", Billy tells Johnny Klebitz about Horse's actions, and how he paid for it.