Sicky

Jessica "Sicky" Unsworth (née Young) is a fictional character and titular tritagonist of the sitcom Cat on the Roof. Seemingly a Devon Rex, she is revealed to be a woman with the ability to shapeshift. Her metamorphosis into a cat is temporary and can be activated either as a coping mechanism to general anxiety, loneliness and frustration, for combat (e.g. a metaphorical catfight), or purely for pleasure. Before encountering the Unsworths, she was a SoHo socialite and destined to be an heiress of a major national bank. However she was ostracized by her family after they discovered about her superpower being used in a fight with a distant cousin at a reunion dinner, and became a stray kitten by 17.

In the earlier seasons, she serves as the main companion of the family and is assigned multiple roles. Sicky attacks intruders and bullies, mediates any arguments to move the story plot forward, is a beacon of beauty, fun and hope, and supports Tucker in his long character development arc. Without Sicky, the family would be joyless. On the other hand, some other characters contend that the family could do with less chaos and more order for true happiness.

The Unsworth family adopted Sicky in her feline form in Season 4, and she married Tucker as a woman in 2010.