Stopgo is a yellow experiment with a long, narrow neck like a traffic pole, and a traffic light-shaped head with a green and red light (most likely his eyes, oriented vertically) on each side of his head.
Stopgo can cause traffic jams by posing as a false traffic light and lighting his eyes up to imitate real street lights
Experiment 102 was the 102nd genetic experiment created by Jumba with Hämsterviel's funding. He was designed to cause traffic jams by posing as a traffic light. 102 and the other first 624 experiments were deactivated and smuggled to Earth by Jumba during his mission to capture Experiment 626.
All of the experiment pods were released and scattered across the island of Kauai.
102's pod was one of the twelve experiment pods recovered by Lilo and Stitch in "Drowsy". His was one of the final four experiment pods (among 204, 274 and 360) that Pleakley, with some assistance from Stitch, cataloged after being convinced to do so by Jumba.
At an unknown point, 102 was presumably activated, tamed, named Stopgo and found a one true place as a traffic light.
Later, the first 624 experiments, including Stopgo, were rounded up by Leroy and taken to a stadium to be destroyed. However, Lilo, Stitch, Jumba, Pleakley, Reuben and Gantu arrived before the experiments could be destroyed.
Stopgo participated in the following battle between the experiments and the Leroy clones, but it is unknown what he did.
The Leroys soon gained the upper hand in the battle, but were defeated when Lilo, Stitch, Reuben and several other experiments performed the song "Aloha ʻOe", which caused the Leroy army to shut down due to the original Leroy's fail-safe.
- Stopgo is Experiment 102. However, in "Drowsy", his pod is called 239, most likely due to Jumba's untidy database.
- Stopgo did not appear activated until Leroy & Stitch.