Abraham deLacey Giuseppe Casey Thomas O'Malley is a friendly alley cat who finds Duchess and her kittens stranded in the woods and befriends them, becoming a father figure to the children. He is the main protagonist in Disney's 1970 feature film, the Aristocats. He was voiced by Phil Harris in the original film, and by Steven Curtis Chapman in House of Mouse.
Thomas O'Malley comes off as a smooth-talking, streetwise cat who relishes his life of freedom out in the open with no rules and no responsibilities. All of this changes when he meets Duchess for the first time. He falls in love with Duchess when he first meets her, and he quickly starts flirting with and serenading her. Although he was obviously a little turned off by the fact that Duchess has kittens, but he and the kittens quickly grow on each other and he becomes like a father to them. Also, when faced with an adversity, O'Malley will indeed rise to the occasion to protect the ones that he cares for and loves.
In the film, O'Malley appears after Edgar kidnaps and tries to get rid of the cats, but is chased off by a couple of dogs. He is instantly attracted to Duchess because of her appearance, but is slightly put off when he learns she has children. However, he soon has a change of heart and helps Duchess and her children get back to Paris safely. During their return to Paris, he becomes smitten with Duchess once again and starts being fond of her children as well as her. In the big fight scene, he and the Alley cats battle Edgar as he tries to send Duchess and her kittens to Timbuktu. He saves Duchess and the kids and becomes a part of the family.
Thomas O'Malley, along with his alley cat friends, made several appearances on Disney's 2001-2003 television series House of Mouse. As a running gag, he and Scat Cat's group were often booked to sing at the club, but an incident of some sort would always result in them being fired (such as Donald booking the Big Bad Wolf to sing instead) or forced to leave (such as being chased by Pluto). In the episode "Max's Embarrassing Date", O'Malley and Duchess are seen next to a tipped table covered in milk after Goofy has an accident.
Thomas O'Malley has become the subject of a popular internet meme about an infamous episode of the UK Gameshow Family Fortunes, in which presenter Max Bygraves asks the question, "Name a famous Irishman." Thomas O'Malley was one of the infamous stupid answers.