Sol, A.K.A. Experiment 554, is an illegal genetic experiment created by Jumba Jookiba. He is designed to consume stars. His one true place is at a solar research facility helping to create a small star.
Experiment 554 was the 554th genetic experiment created by Jumba with Hämsterviel's funding. He was designed to consume stars (does so by using his incredible speed and metabolism, able to withstand incredibly high temperatures which allows him to survive on the surface of any star he targets, also able to fly and even break orbit in order to reach his next destination; once a star has been consumed in its place he leaves a small explosive capsule that contains the power of the star he consumed, these capsules are very sensitive and detonate without warning. ).
554 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 an unknown point, 554 was activated, captured, tamed and named Sol.
He is oughly the size of a bus.