Rigsy

"Rigsy" was the self-appointed pseudonym of a graffiti artist from Bristol, whose criminal activity saw him sentenced to community service. He helped Clara Oswald fight the Boneless. Rigsy's aunt was one of many people in Bristol who had been experimented upon by the Boneless. Rigsy attempted a self-sacrifice to ram an empty subway commuter train into them, which needed a person to hold the dead man's lever in place so it would remain in operation. Clara, however, used a headband to restrain the lever instead and let the train run with nobody inside, saving Rigsy from an unnecessary demise. Rigsy later used his artistic skills to create a fake door, which tricked the Boneless into charging the TARDIS because the door never existed in 3D, and the Boneless tried making his art 3D. (TV: Flatline)