Wiggles is a plush toy that Missy uses for dry humping. Closely resembling a Playskool Glo Worm, Wiggles first appeared in "Dark Side of the Boob", where he speaks to Missy, and we learn they've been "worm dancing" for quite some time.
When bidding Wiggles goodbye in "Smooch or Share", Missy fondly recalls previously bringing the toy to a socialist Sleepaway Camp. Wiggles and Missy are ultimately reunited and celebrate with more masturbation.
Mona encourages Missy to "go digging in her garden" with Wiggles in "The Apple Brooch".