If you’re from Western Europe, you will know who these characters are.
If you aren’t, know that they are Asterix the plucky Gaul, his big pal Obelix, and their pet dog Dogmatix, creations of French comic writer and artist René Goscinny and Albert Uderzo. They are the equivalent of Mickey Mouse and Donald Duck in France. Asterix and Obelix lived in the time of Julius Caesar, and many of their adventures concern outwitting the Roman leader and his troops. (They also had run-ins with Cleopatra.) They even have their own theme park.
If you need an imaginary Gaulish tribe for worldbuilding purposes, here’s a few randomgen ones.
Imaginary Gaulish Tribes