Professor Achilles Milo is a villain and enemy of Batman.
A renowned chemist who turned to crime, he used a variety of chemical and medical-related schemes to kill Batman involving subjecting Batman to a drug that made him afraid of anything bat-shaped, gassing Batman with a compound that made him lose his will to live, manipulating the werewolf-like Anthony Lupus into doing his bidding, taking control of Arkham Asylum, and attempting to make Batman insane with yet another gas.
Milo was later exposed to chemicals that drove him insane, and he spent some time in Arkham Asylum. Batman consulted him on at least one occasion when he needed chemical expertise given to him by The Joker. After that, Dr. Milo retired from criminal activity. He appeared in Arkham Asylum: A Serious House on Serious Earth, where the gas had apparently worn off, but he couldn't convince anyone he was actually sane.
In 52 week 41, Ralph Dibny confronts an emaciated Doctor Milo, who appears without his lower legs, and in a wheelchair, which is actually used to disguise the Silver Wheel of Nyorlath.
In Batman R.I.P., a past hallucination induced by Professor Milo's gas is revealed to have inspired Bruce Wayne to create the 'back-up' personality of the Batman of Zurr-Enn-Arrh, a more ruthless Batman personality designed to take over in the event of Bruce Wayne being psychologically attacked in such a manner as to render Batman out of action.
In other media
DC Animated Universe
- Main article: Professor Milo (DC Animated Universe)
Batman: The Brave and the Bold
Professor Milo appears in the episode "Gorillas in Our Midst" where he trained rats to steal diamonds. He is beaten by the Spectre and Batman. When Batman has left the Spectre turns Milo into cheese and releases his rats which devourer him.
Batman: Arkham Underworld
Professor Milo appears in the mobile Arkhamverse video-game Batman: Arkham Underworld as an NPC. In the game the player can purchase and build a lab for Milo who can in-turn upgrade the powers of the player's super-villains.