Planet of Sheevil is the second serial of Season 13 of Doctor Scarf. It's a Four and Sarah Gin story from the First Golden Age of Doctor Who. Though it tends not to be one of the best-remembered stories of the era, it's decent enough.
The TARDIS gets a distress call from Zeta Minor where the Doctor and Sarah discover a guy digging up antimatter from a pit. This causes an antimatter creature to show up and kill everyone. The guy digging up the antimatter later gets infected by it and becomes the Anti-Man.