Not much is know about Taurus Bulba's background. Taurus is shown serrving a 99 year jail sentence yet still involved in criminal affairs from the prison. In fact, he seems to find being incarcarated to only be a minor inconvience, seeing his prison cell as the perfect hideout and cover for his activities.
After his henchmen stole the Waddlemeyer Ram Rod (an experimental weapon that seems to envelop its targets in an anti-gravity field, destroying buildings and the most heavily-guarded banks) Bulba escaped and gave orders to kidnap Gosalyn because he believed, as she was Professor Waddlemeyer's only living relative, that she knew the secret code to active the Ramrod. At the end of Darkly Dawns the Duck, Bulba forced Darkwing to give him the arming code by threatening to drop Gosalyn to her death. ("She'll make a rather nasty stain on the pavement.") Darwkwing fought Bulba and ended up destroying the Ram Rod, as well Canard Tower. Though heavily injured, Darkwing survived, but Taurus was presumed killed in the explosion. Thanks to the efforts of F.O.W.L, Bulba managed to survive and was made into a cyborg.
F.O.W.L. subsequently assumed that Bulba would accept their offer of employment following their restoration of him. Bulba...pointedly declined the offer and elected to attempt to gain revenge on Darkwing and Gosalyn. After being once again defeated by Darkwing and Gosalyn, he manages to flee, swearing that he would get his revenge.
Taurus Bulba returns, as the CEO and mastermind behind the mega-corporation Quackwerks, in an attempt to get revenge on Darkwing Duck and his companions, but more importantly, to give St. Canard a new kind of villain, as he considers the other villains unprofessional.
Apart from some comedic moments, Taurus Bulba is considered to be a dark and menacing character, and probably the most malicious villain ever to appear in the series. In Darkly Dawns the Duck it is strongly implied his henchmen murdered Gosalyn's grandfather , by claiming it was an "Accident", and his men and pet condor Tantalus also nearly kill Gosalyn as well.
Gosalyn is afraid of him.
Taurus Bulba has returned from prison to join the Organization as the leader of St. Canard and Duckburg's numerous Rouges Gallery. His armor has also been upgraded to unleash dark magic upon his opponents.