When SpongeBob and Patrick are pet sitting for Sandy, they and Wormy play games such as hide-and-seek and tag. However, overnight, Wormy quickly metamorphoses into a butterfly and scares everyone in Bikini Bottom because they mistake him for a monster and have never seen a butterfly before.
After Sandy returns from her trip and captures Wormy in a jar, the Bikini Bottomites celebrate, prompting Sandy to believe that she did not know she had been missed so much and should leave town more often.
Wormy is seen flying in space among asteroids and other pieces of junk.
In The SpongeBob Movie: Sponge Out of Water, a poster of Wormy in his butterfly form can briefly be seen in Sandy's treedome. The image of Wormy on the poster looks very similar to the one seen on the "Beware" fliers made by SpongeBob and Patrick.
The close-up shot of Wormy in his butterfly form is actually footage of a buzzing horsefly.
This footage is royalty-free, and owned by Oxford Scientific Films.
When Wormy's close-up is shown, the horsefly was making buzzing sounds, however, butterflies do not make buzzing sounds, even though it is a characteristic of flies in general.