Mat Irvine is probably best-known for his work as a Technical Consultant and Visual Effects Designer who worked on television, primarily for the BBC, from the 1970s to the 1990s. As a Technical Consultant, Irvine worked on shows such as The Sky at Night , Tomorrow's World and the original series of Robot Wars . As a Visual Effects Designer, Irvine worked on shows such as Rentaghost , T erry and June , Blake's 7 , The Tripods , Edge of Darkness and To the Manor Born . He is perhaps best known for his work on Doctor Who , for which he was a Visual Effects Designer, from the 1970s to the 1980s. He is credited with building the first K-9 prop for the program. Nowadays, he makes appearances at sci-fi and Doctor Who conventions, often alongside K-9, which he still operates. He also organizes and runs regular models shows.