Anthony "Tony" Romulus was an Olympic athlete and philanthropist turned monster.
Tony Romulus competed in several prestigious competitions, usually being very successful. The fame and power went to his head, however, and he felt the need to become even more successful when he qualified for the Gotham Games. Like many athletes, Tony Romulus stuck to a strenuous exercise program, but still he was unsure of placing in the forthcoming event. This was a matter beyond the customary lack of confidence that many deal with; Tony's desire for success caused him to look for "something that would guarantee him a gold medal", but knew he could not take anabolic steroids as the games committee was clearly on the lookout for doping athletes. He eventually called upon Professor Milo to aid him. Milo came up with a serum possessing wolf hormones, a serum that would be untraceable in any drug test the games committee administered. Romulus hastily accepted, not knowing he had been tricked by Milo. Afterwards, his expanded incredibly, having become the best athlete in any competition. The serum had horrible side effects, however, as Anthony was eventually transformed halfway into a werewolf during a night of the full moon. When he came to Milo for help, Milo revealed that he couldn't cure Romulus in his present state as there was none. However, he did have a cure for complete lycanthropy and so he made Anthony a bargain; he would complete his transformation into a full werewolf, however Romulus would have to obey certain orders given to him by Milo, including the elimination of persons who Milo considered dangerous to his work. Romulus accepted and was fully transformed into a werewolf, which he would become during nights when the moon was full.
Romulus caught the attention of Batman when he — known simply as "a wolf-like creature" — was spotted at the Gotham Zoo attacking a guard who had information that could lead back to Milo. After reporting that he had encountered Batman whilst on his attempted assassination, Milo decided that they needed to get him out of the way.
Romulus then put out word that he wished to make a charity donation, that he would only sign over if Batman accepted. When explaining why to Bruce Wayne, who was an associate of Romulus from their gym, he mentioned he merely wished to meet Gotham's 'second-best athlete'. Later during the night, Batman arrived in Romulus' study, with the intent on picking up the cheque as quickly as possible. However, it was all revealed to be a trap, as Romulus activated knock-out gas from his venting system and incapacitated the Dark Knight.
Romulus and Milo then brought Batman to Milo's secret workplace, at the under-construction Gotham Coliseum. They chained Batman in the middle of the arena, with Milo intent on having Romulus transform and kill Batman whilst he was immobile. Despite everything, Romulus refused and pressed Milo for the cure. When Anthony feels the transformation about to happen, Milo however quoted "ask me if I care". Anthony transformed and attacked Milo trying to kill him and ignored his orders with the supposed cure being destroyed in the process. Milo barely escaped Romulus, who then turned his attentions on Batman. Batman was luckily able to free himself just before Romulus attacked and proceeded to fight back against him, now a wild uncontrollable beast. Batman was somewhat of an underdog in the fight, but held his own. Eventually as the fight continued to the tallest exteriors of the structure with the police arriving, Romulus was seemingly defeated when he was struck by lightning and knocked off the edge into the nearby river. After Dr. Milo is loaded into the ambulance, Detective Harvey Bullock tells Commissioner James Gordon that he and the other police officers were unable to find the werewolf upon searching miles of shoreline. Harvey Bullock snidely remarked that they would wait until the next full moon, then they would know for sure whether the werewolf was alive or dead. Months later as Romulus' former mansion was purchased, a wolf-like creature was seen howling at the full moon. What happened to Anthony still remains unknown to the public.
Issue #21 of The Batman Adventures (a comic book based on the animated series) brought back Anthony Romulus' werewolf form and Tygrus alongside Man-Bat when they are used by the recently escaped Doctor Emile Dorian to capture Catwoman. Emile forcefully transformed the unwittingly Kirk Langstrom to help him. Romulus wanted Emile to return him to normal in exchange for his service. Tygrus, Dorian and Romulus are all apparently killed in an explosion that ensues.
Anthony was already a superb athlete before he took the wolf serum. After taking the serum, he virtually became the best in every field, beating his competitors seemingly without effort. After his complete transformation into a werewolf, which would happen every full moon, his wolf form would be even larger, more powerful and more ferocious than he could ever hope to be in his human form. He had no speech or recognizable thought capabilities whilst changed, but his more bestial instincts easily proved to be dangerous enough to eliminate to need for such. Batman himself noted that in a fair physical fight on even ground, he would be no match for Romulus as a werewolf and was forced to find smarter tactics.
For reasons unknown that character's surname was changed from Lupis to Romulus for the cartoon, despite the fact that the episode was scripted by one of the character's creators from Batman issue #225, Len Wein.