Thomas, A.K.A. Experiment 369, is an illegal genetic experiment created by Jumba Jookiba. He is designed to be a train.
Experiment 369 was the 369th genetic experiment created by Jumba with Hämsterviel's funding. He was designed to be a train.
369 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.
At the unknown point, he was activated, captured, tamed and named Thomas.
Thomas is a blue train-like experiment that literally resembles Thomas the Tank Engine.