Swell, A.K.A. Experiment 541, is an illegal genetic experiment created by Jumba Jookiba. He is designed to grow bigger due to being engorged or ignored.
Experiment 541 was the 541st genetic experiment created by Jumba with Hämsterviel's funding. He was designed to grow bigger due to being engorged or ignored.
541 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 Swell.