Abraham deLacey Giuseppe Casey Thomas O'Malley is the deuteragonist 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.
- 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.
- In the Italian dub, O'Malley is known as "Romeo." He's Roman and his most famous sentence is "Io so' Romeo, er mejo der Corosseo" ("I am Romeo, the best of the Colosseum").
- Thomas O' Malley has notable similarities to Tramp.
- Both were stray animals.
- Both fall in love with a house pet. (Lady, Duchess)
- Both roamed wherever they wanted before marrying their love interests.
- Both heroically saved the main characters from time to time.
- Both try to convince their loved ones to stay with them, but fail.
- Both come to their loved ones' rescues in the climax. Tramp goes to save the baby from a rat to Lady's urgings, and Thomas O' Malley saves Duchess and her kittens from being shipped off to Timbuktu.
- Both settle down to become fathers (and on a minor note, also have family photos taken).
- Both have a son who looks like them. Scamp looks similar to Tramp and Toulouse looks similar to Thomas.