Milo was described as "plump, round-faced, sleek-haired with an air of bland cheerfulness." He was an Arcalian and wore its green robes. He was a natural philosopher and treated everything like an intellectual joke, such as the embarrassment of putting the Second Doctor to death for violating the non-interference policy, (TV: The War Games) just as they were about to do the same thing. (PROSE: World Game) Milo was wary of Sardon and understood the man was powerful.
It was Milo's task to lock and unlock a Time ring around the Doctor's wrist, guaranteeing his obedience. He had more traces of compassion than his peers, understanding the Doctor would make a better ally if he served them willingly. Nevertheless he was a little complacent, and didn't see the need to keep the Doctor under supervision. He was unpleasantly startled when Serena found him about to be shot by a firing squad. After rescuing him he asked the Doctor if he could go anywhere without getting into trouble.(PROSE: World Game)