Mark Griffiths scripted Cutaway Comics' four-part miniseries Omega. In the synonymous audio adaptation, Griffiths played guards, radio voices and Omegans.
He also wrote The Decades Collection novel The Self-Made Man, the Origin Stories short story Murmuration, and The Adventures Before short story The Boy and the Dalek.
He was described in Issue 1 of Omega as "a comedy writer, author and playwright". It was highlighted that, under the pen name of Mark Powers, he created the Spy Toys series of children's books.