Autumn, A.K.A. Experiment 538, is an illegal genetic experiment created by Jumba Jookiba. She is designed to turn season into autumn. Her one true place is on a farm, causing fruit to ripen early so the farmers can have more crops.
Experiment 538 was the 538th genetic experiment created by Jumba with Hämsterviel's funding. She was designed to turn season into autumn.
538 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, she was activated, captured, tamed and named Autumn.
Autumn is a small brown koala-like experiment with leaves around and grapes on her head, two bent antennae, fairy-like wings and a stick-like wand on her hand.
Any plant that Experiment 538 touches with her wand starts to behave like autumn has come.