The Black Rider is the name of several Western heroes in the Marvel Universe.
Matthew "Doc" Masters[]

The Black Rider (Matthew Masters) was a masked crime fighter in the old west, called such as he was dressed completely in black.
Origin[]
Doc Masters' parents were killed by a vicious criminal and spent his life working to avenge them. After killing his parents' killer, Masters became a doctor and tried to be a man of peace. After one of his patience was murdered by a criminal and decided to live a double life as a crime fighting masked vigilante known as the Black Rider.
Biography[]
Though Matthew Masters birthplace and hometown are unknown, he was raised by his parents, Ned and Jezebel Masters, in a small west town. At age five, they were both killed by a looter named Luke Davis, which left the boy with a hunger for justice. Matt swore vengeance and was able to learn to shoot by age thirteen and as a teenager earned a reputation as a gunslinger, earning the nickname The Cactus Kid.