What is the name of Tommy's younger brother introduced in the first movie?

Tommy’s younger brother introduced in the first Rugrats movie is Dil Pickles. His birth is the central new development in The Rugrats Movie, released theatrically in 1998.

Dil’s arrival changes Tommy’s place in the family. Tommy initially struggles with jealousy because the adults focus so much attention on the new baby, while Dil’s constant crying frustrates the older children. The babies eventually take Dil away in the Reptar Wagon, setting the movie’s wilderness adventure in motion.

Dil’s full name is Dylan Pickles, and he is the younger son of Stu and Didi Pickles. Unlike the other babies, Dil is too young to speak clearly in the early stories, so his behavior and cries become a major source of comedy and conflict. His presence also expands the Pickles family dynamic beyond Tommy and Angelica.

Dil remains part of the television series after the film and appears in later Rugrats stories, including the crossover movie Rugrats Go Wild. The first film therefore serves both as a standalone adventure and as Dil’s introduction to the franchise.