Richard Timothy Smith (born 25 March 1942), better known under his stage name Richard O'Brien, is an English writer, actor, television presenter and theatre performer. He is known for writing the cult musical The Rocky Horror Show and for his role in presenting the popular TV show The Crystal Maze. In addition to writing The Rocky Horror Show, O'Brien also co-wrote the screenplay of the 1975 film adaptation The Rocky Horror Picture Show, and appeared in the film as the character Riff Raff. The stage show has been in almost continuous production and the cinematic version, which has been in continuous release, is one of the best known and most ardently followed cult films of all time. He is also the voice of Lawrence Fletcher, the title characters' father in Phineas and Ferb.