Cat is an elderly, furred cat. He is taller than the other Freedom Fighters, who are all teenagers, and his tail is about half of his height in length. Cat's fur is dark brown; whilst his thick eyebrows and stomach fur are a faded blonde. He also has grey fur on either side of his muzzle and his eyes are olive.
Cat joined Sonic, Antoine and Princess Sally in a mission in Robotropolis, infiltrating the city via an air duct. While Sonic and Sally went to try and reprogram a plane, Cat and Antoine remained in the air duct to guard their escape route. However, Antoine was very nervous. When Cat suggested he relax, Antoine leaned against the vent and fell out of the duct, revealing the group's presence to a Swat-bot. The mission blown, Cat, Antoine and Sally escaped through the duct while Sonic created a diversion. However, one Swat-bot followed them. Cat, who was bringing up the rear, spotted the Swat-bot and decided to lead it away from the others, down a different tunnel. Although he allowed the others to get away, he was soon captured and brought before Doctor Robotnik, who attempted to make Cat reveal the location of Knothole. However, Cat refused to talk, and he was sent to the detention center.
Soon after, Sonic returned to Robotropolis to rescue him. However, Cat had learned that Robotnik's surveillance had detected Sally heading for the Dark Swamp, and sent Sonic to go and protect her. When Sonic asked what would happen to Cat, he replied that it didn't matter. In the end, the decision was made when a group of Swat-bot interrupted them, forcing Sonic to leave before he could free the old Freedom Fighter.
When Sonic returned to Cat's cell after ensuring Sally and Antoine's safety, he found it empty. Understanding that he had lost his friend, Sonic dedicated his next mission, destroying Stealthbots, to Cat's memory. Cat's exact fate was not revealed, though it is implied that he was either killed, or roboticised.
Cat is very loyal, sacrificing himself to protect his friends. He also comes across as being calm and not losing his head when faced with a difficult situation.