Berlioz is usually very quiet, but mischievous. He enjoys playing the piano, as seen when Duchess asks him to practice his Scales and Arpeggios with his sister Marie. He isn't easy to impress and can be annoyed rather quickly, usually he's the first to make a snide look or comment toward things he doesn't like. Still, he's shown to be just as naive and sweet-natured as his siblings.
Berlioz has blue eyes, dark grey fur (practically dark green fur) with a lighter stomach. He also wears a small red ribbon around his neck that is tied. Being a kitten, he's fairly small.
Role in the film
Berlioz first appears in The Aristocats during the opening credits, which display some of the scenes that he will appear in later.
Berlioz is next seen during the carriage ride during the beginning of the movie, where he rides on Frou-Frou's head. At the end of the carriage ride, his mother, Duchess, reminds him to thank Frou-Frou for letting him ride on her head (which he does). After asking how his thank you was, Duchess comments, "That was very nice."
Later, Berlioz is in a race with his siblings to see who goes through the front door first. When Marie states that she has the right of way, Berlioz sides with Toulouse's argument that Marie isn't a lady, even going as far to say that she is "nothing but a sister." Soon, Berlioz ends up in a fight with his sister (with Toulouse encouraging his brother from the sidelines). Berlioz tickle tortures Marie but ends up receiving punishment when his sister refuses to fight fair by tugging at his bow tie. Eventually, the fight ends when Toulouse accidentally knocks down a candle and it lands on Marie’s head. Duchess comes in to break up the fighting, insisting that fighting would not make them sophisticated (stating later that "Aristocrats do not practice biting and clawing and things like that"). Berlioz insists that Marie started it, while Marie retaliates, "Ladies do not start fights, but they can finish them!"
Soon enough, it is time for the family to concern themselves with self-improvement. While Toulouse goes to practice painting, Berlioz and Marie go to the piano to practice their music. Though there is a brief tiff between Berlioz and Marie when (thanks to Berlioz's piano-playing) Marie gets her tail squished, the fight ends and "Scales and Arpeggios" begins. Berlioz gets a little show-offish and, after Toulouse decides to join in on the playing, Berlioz and he end up in a piano battle that ends in a draw.
Later that evening he and his family are enjoying their dinner when they fall asleep. After a bump ride, he lands in a pond. He and his family later encounter Thomas for the first time. They go on a few adventures with him on a milk van and on a train bridge. Later the cats encounter Scat Cat and his friends and party.
A while later, they return to the mansion but their door is shut. They try to mew their way in but get captured by Edgar. The sack is sent into an old oven where Toulouse brags to his siblings that he was right that Edgar tried to get rid of them which annoys him and Marie. He and his family get rescued by the musician cats and watch as a defeated Edgar is mailed to Timbuktu instead of them. He is seen getting a picture taken then running downstairs to join the party.
Berlioz, along with his brother Toulouse, oddly never appeared in "live" form at any of the Disney theme parks until February 2013, in Disneyland Paris for a Valentine's Day Event. He alongside Toulouse make occasionally meet and greet appearances at the resort.
Berlioz alongside Toulouse made their debut at Tokyo Disneyland in 2013 for the former daytime parade Happiness is Here Parade as part of the park's 30th Anniversary. Berlioz appears on The Aristocats float that's a giant piano along with Marie and Toulouse. Berlioz also makes meet and greet appearances at both Tokyo Disneyland and Tokyo DisneySea.
Berlioz shows up at Shanghai Disneyland for the park's daytime parade Mickey's Storybook Express alongside Marie and Toulouse. Berlioz along with the other kittens also appear at a daytime show near Fantasyland.
Berlioz alongside Toulouse also made their U.S. debut at Disneyland in mid-November 2019 as part of a Christmas Dance Party in Tomorrowland alongside Marie.
While Toulouse alongside Berlioz have yet to make live appearances at Walt Disney World, the "Aristocrepes" stand at Disney Springs, which sells crepes, features silhouettes of Marie, Toulouse, and Berlioz on the stand's logo. At Disney's Riviera Resort, Marie, alongside Toulouse and Berlioz, are presented on some murals inside the resort.
- Berlioz was named after a French romantic composer named Hector Berlioz.
- His Italian name is "Bizet", a reference to the musician/composer Georges Bizet.
- Berlioz resembles a younger version of Scat Cat. However, Scat Cat is grey with white patches around his eyes and nose, and Berlioz is completely grey, as noticed, they both wear the same red ribbons.
- In some of the books, Berlioz can sometimes be mistaken as Toulouse, similar to how Toulouse can be mistaken as Berlioz.