Achilles Milo was a freelance scientist, possibly without a degree. Shifty and unscrupulous, he was known in the underworld as Professor Milo. Milo was hired by Roland Daggett to create a deadly viral plague to unleash upon Gotham City (with Daggett Industries having the only cure, of course). Milo's job was to infect captured stray cats and dogs with the virus, then release them into the city. He was stopped by Batman when he and Jessie fell through thin ice over a lake while they were attempting to kill the Dark Knight on Daggett's orders.
Milo got out of jail, and was approached by Anthony Romulus for help in winning some sports competitions. He gave Romulus a special steroid derived from timber wolf DNA, using wolves stolen from the Gotham Zoo with the help of John Hamner, but this accidentally turned Romulus into a werewolf. Milo then tried to use the beast to get revenge on Batman. However he was unable to control his creation, and attacked by it. He survived, and was arrested again.