Take a tip from Bill Sikes, He can whip what he likes, I recall he started small, He had to pick a pocket or two.
~ Fagin, singing about Bill Sikes in the film.

Bill Sikes is the main antagonist of Oliver Twist. Although Fagin and Mr. Bumble are sometimes regarded as antagonists it is Bill Sikes who provides the true villain to the story due to his violent nature and criminal tendencies - which surpassed the thieving ways of Fagin as well as the child abusing ways of Mr. Bumble and ultimately led to murder.

Bill Sikes was a brute who regularly beat his own bull terrier to the point the animal required stitches and had no remorse over using Oliver to further his criminal gain, he was involved in a relationship with the kindly Nancy but brutally murdered her when he feared she had betrayed him - the murder Sikes committed was one of the most graphic and disturbing acts of violence that Dickens had written and transformed Sikes at once into a monster.

Bill Sikes would meet his end however when he hung himself from the street rafters while trying to escape from an angry mob that had formed to hunt him down (in the 2007 miniseries he committed suicide by hanging himself in the sewers of London).

He is also the main antagonist of the play and film adaption of Oliver!. He doesn't sing in the actual film, but he does in the stage musical.