Anthony "Tony" Romulus was a pentathlete and philanthropist turned monster.
Romulus competed in several low-level competitions, usually being very successful. The fame and power went to his head, however, and he felt the need to become even more successful. Romulus got his chance when his earlier victories allowed him to compete in Autumn Games.
Despite his dedication to strength training and proper exercise, Romulus' need to succeed led him to search for something that would guarantee him a gold medal. He eventually called upon Dr. Milo, who knew that he could not use anabolic steroids, as the games committee was clearly on the lookout for doping athletes. He instead concocted a serum possessing timberwolf hormones, which was obviously not a chemical the games committee would look for, and thus wouldn't be flagged in drug tests. Romulus hastily accepted, not knowing he had been tricked by Milo. Afterwards, his career expanded incredibly, having become the best athlete in any competition. After receiving the gold medal and enormous fame and fortune, Romulus was able to secure himself endorsement deals. He spent his money on a mansion and sports cars, then began dating attractive starlets. However, when Milo came around asking for his share of the winnings, Anthony threw him out, claiming Milo was no longer needed.
The serum had horrible side effects, however, as Romulus was eventually transformed halfway into a werewolf during a night of the full moon. When he came to Milo for help, he said that Romulus had moderate lycanthropy, as evidenced by his shaggy appearance but lacking animalistic tendencies. Romulus pleaded for a cure, to which Milo claimed he could not treat the stage of lycanthropy he was in. However, he did have a cure for advanced lycanthropy and so he made Romulus a bargain; Milo would complete his transformation into a full werewolf to be properly treated, but Romulus would have to do everything he says, including the elimination of people 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.
As a dangerous beast, Romulus caught the attention of Batman when he was spotted at the Gotham Zoo attacking John Hamner, a guard who had information that could lead back to Milo. Romulus managed to escape once his assassination attempt was thwarted and went back to Milo. After returning to his human form, he reported his encounter with Batman and Milo decided that they needed to get him out of the way.
Romulus then told the press that he would double a donation he had promised to charity, but he would only sign the check should Batman be the one to accept it. 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 him.
Batman was then bought 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 while he was immobile. When Romulus transformed into a werewolf form, it made him so aggressive that he even attacked Milo, ignoring his orders. In fear, Milo dropped the vial containing the supposed cure, angering the werewolf, who then flung him into a ditch where he was knocked unconscious.
Batman was luckily able to free himself just before Romulus attacked and proceeded to fight back against him, now a wild uncontrollable beast. Eventually as the fight continued to the tallest exteriors of the structure, Romulus was seemingly defeated when he was struck by lightning and knocked off the edge into the river. Milo was arrested, but the police were unable to find the werewolf upon searching miles of shoreline. Harvey Bullock snidely remarked that they would wait until the next full moon.
Months later, Romulus' savings were depleted and his mansion was seized to pay back taxes and his legal creditors. One married couple looked at buying it, to which the real estate lady explained that there were rumors that Romulus skipped town. The couple wondered why someone who had it all would suddenly abandon it.
Later, a wolf howled at the full moon. It was implied that Romulus's condition may now be permanent.
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 with record-breaking performances 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 the 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 devise smarter tactics.
Anthony's human appearance is modeled on a typical stereotype of classic 30/40's era Werewolf films—he has a unibrow and is a wealthy man—whereas his Wolf form is closer in appearance to creatures seen in The Howling (which Dick Miller, Kevin McCarthy and Robert Picardo had acted in).
Though he made no more appearances in the animated series, he resurfaces in The Batman Adventures #21. He has an encounter with Emile Dorian (who had escaped from Arkham Asylum) and joins up with him in exchange for a cure that would restore his human form. Man-Bat, Tygrus, Dorian and Romulus are all apparently killed in an explosion at the end.