Cartoon character "Top Cat" is the leader of which gang in the TV series by Hanna-Barbera?

Top Cat is an American animated television series made by the Hanna-Barbera studios that first ran from September 27, 1961 to April 18, 1962 for a run of 30 episodes on the ABC network.

Originally broadcast on Wednesdays (8:30–9pm Eastern), Top Cat was co-sponsored by Kellogg's and Bristol-Myers (Bufferin). The central character, Top Cat (called T.C. by close friends, "pro-vi-ding it's with dignity" according to the lyrics of the theme song) is the leader of a gang of Manhattan alley cats living in Hoagy's Alley: Fancy-Fancy, Spook, Benny the Ball, Brain, and Choo Choo.

Top Cat and his gang were inspired by the East Side Kids, characters from a series of popular 1940s 'B' movies, but their more immediate roots lay in The Phil Silvers Show, a late-1950s military comedy whose lead character (Sergeant Bilko, played by Silvers) was a crafty con-man. Maurice Gosfield, who played Private Duane Doberman in The Phil Silvers Show, provided the voice for Benny the Ball in Top Cat, and Benny's rotund appearance was based on Gosfield's. Additionally, Arnold Stang's vocal characterisation of the lead character, the eponymous Top Cat, was based on an impression of Phil Silvers' voice.