Professor Milo and Professor Fether were at one point the administrators of the infamous Arkham Asylum on their respective twin worlds. Using experimental hallucinogenic drugs, they gained temporary mastery of the Guardians of Gotham, the Batman and the Huntress.
On Earth-One, Milo dappled in a variety of sciences. Once he tampered with Batman's mind causing him to fear his caped alter ego. As "Starman", the Dark Knight was able to defeat Milo, who later used chemicals to transform a man named Lepus into a wolf-man. During the Arkham episode, Milo was able to con his way into an administrator role there, although the treatment he sought to use on his foe he himself became subjected to. This led to him being an insane inmate there.
On Earth-Two, Fether alongside co-conspirator Doctor Tarr had a criminal enterprise wherein they funneled criminals through their system through a third party contractor known as the Undertaker. However, Huntress was able to ferret out to their schemes, leading to her capture and being subjected to Fether's chemical concoction. Although she was adversely effected with longtime mental fragmentation resulting which she had to battle through, Huntress was able to stir a prison revolt wherein the inmates overpowered their wardens. Now in custody, Tarr and Fether's criminal careers were finished for good.