The Pickles family's dog in "Rugrats Go Wild" is named Spike. He is Tommy Pickles' loyal animal companion and one of the most recognizable recurring characters in the Rugrats universe.
Spike is presented as a large, unusual dog whose fictional breed is described as a Siberian tiger hound. The character's design combines features associated with several animals, including a Basset Hound-like face, a bloodhound-like head, and tiger-like markings and paws. The exaggerated design fits the show's playful cartoon style.
In "Rugrats Go Wild," Spike travels with the Pickles family and encounters Eliza Thornberry, who can understand animals. When Spike says that his "babies" are missing, Eliza initially assumes he means puppies. She eventually realizes that he is referring to Tommy and the other human babies, whom Spike treats as members of his family.
The 2003 crossover film featured Bruce Willis as Spike's speaking voice. Spike also appears in the earlier Rugrats films and throughout the original animated series.