Tom and Jerry: The Kid Who Would Be King is an upcoming fantasy adventure film, produced by Warner Bros. Pictures (WarnerMedia Byline), WB Animation, 20th Century Fox, TSG Entertainment, Metro-Goldwyn-Mayer Pictures and Working Title movie based on 2019 film (The Kid Who Would Be King).
- Tom Cat - A grayish-blue cat, who is Jerry's rival, Tuffy and Lucy's friend, Uncle Harry's boss, Toodles' husband, and Tin, Pan and Alley's rival, boss and friend. In this movie, he is Alex's pet cat along together with Jerry and Tuffy and he's the Knight-cat.
- Jerry Mouse - A brown-orange mouse, who is Mrs. Mouse's son, Tom's rival, Tuffy and Lucy's uncle, Grandpa's grandfather, Uncle Harry's grandnephew, Geraldine's brother, Cherie's husband, and The Mouse Queen's fiancée and a good friend of Troops the blue-uniformed soldiers mice. In this movie, he is Alex's pet mouse along together with Tuffy and Tom and he's the Knight-mouse.
- Tuffy Mouse - A young baby grey, diaper-wearing mouse, who is Jerry and Cherie's nephew and son, and The Mouse Queen's little fiancée and a good friend of Troops the blue-uniformed soldiers mice, Lucy's boyfriend, Grandpa and Uncle Harry's grandnephew, Mrs. Mouse's grandson, Geraldine's son and Tom's friend. In this movie, he is Alex's pet mouse along together with Tom and Jerry and he's the Knight-mouse Jr.
- Alexander "Alex" Elliot - Mrs. Elliot's son and Tom, Jerry and Tuffy's owner and friend.
- Bedders - Alex's best friend.
- Lance -
- Kaye -
- Morgana - An evil sorceress and old enemy of Merlin, her half-brother King Arthur, and all of Camelot.
- Tin, Pan and Alley -
- Merlin - A wizard who was an ally of King Arthur. Because Merlin ages backwards, he has the appearance of a teenager after centuries have passed.
- Droopy Dog - A white dog. In this movie, he helps with Merlin.
- Toodles Galore - A white cat, who is Tom's wife, girlfriend, love-interest and always looking at her white-buttocks and Cherie's friend and she's the student female cat.
- Cherie Mouse - A purple scarf, shirt and wearing a light-brown mouse, who is Jerry's wife, girlfriend and love-interest, Lucy and Tuffy's aunt and always looking at her light-brown buttocks, Mrs. Mouse, Geraldine, Grandpa Mouse and Uncle Harry's twin sister and Toodles' friend and she's the student female mouse.
- The Mouse Queen - A light-grey in a dark-blue dress with yellow crown, who is Jerry Mouse's love-interest, with her troops, Tuffy, Lucy and Quacker's friend and a good friend of Mrs. Mouse, Cherie Mouse, Uncle Harry, Grandpa Mouse, Geraldine Mouse and Tom Cat.
- Troops - The Mouse Queen's blue-uniformed soldiers mice and a good friend of Jerry, Tuffy, Lucy, Quacker, Mrs. Mouse, Cherie, Uncle Harry, Grandpa Mouse, Geraldine Mouse and Tom Cat.
- Quacker -
- Lucy Mouse -
- Grandpa Mouse -
- Uncle Harry -
- Mrs. Mouse -
- Geraldine Mouse -
- Mrs. Elliot - Alex's mother.
- Sophie - Alex's aunt.
- Mrs. Lee -
- Mr. Kepler -
- Mr. Jeffreys -
- Ms. Foster -
- Mr. Hyde -
- Stonehenge Tour Guide -
- Rated PG (Parental Guidance) with mild threat, scary scenes, violence, language.
- Suggested Running Times: 120 Minutes (NTSC), 115 Minutes (PAL).