Tab_ the Clocat

Tab is the vicious cat of Nuthanger Farm who appears in the book, movie and miniseries.
Book
In the book, Tab is a male cat (but portrayed as a female in the movie) who taunts his prey. He also has a sort of ambition to kill Hazel. When Hazel and Pipkin were trying to steal some hutch rabbits - Clover, Boxwood, Haystack, and Laurel - from the farm, Tab tried to creep up on them. Pipkin spotted him, however, and Hazel taunted the cat into jumping at them before they made their escape.

Later during the Battle of Watership Down, after Hazel released the fierce guard dog, Bob, Tab went after Hazel and caught him. However, the cat's owner, Lucy, saved Hazel's life.

Miniseries
Tab appears in the miniseries where unlike the film, he does not speak. Unlike previous versions, it is Fiver whom Tab attacks near the end of the film instead of Hazel, only to be stopped by Lucy, who later releases Fiver back into the wild.

Tab was portrayed as a dangerous opponent to rabbits, being strong enough to defeat Bigwig, though having an advantage by attacking from ambush, and intelligent enough to use a vase to awaken the farmer's wife. Tab is shown to be very determined to hunt the rabbits, going so far as chasing them over the glass roof.