Who remembers Underoos! Underoos was a brand of underwear for children, produced by the Fruit of the Loom company. The packages include a matching top and bottom for either boys or girls, featuring a character from popular entertainment media, especially superhero comics, animated programs, and fantasy/science fiction. In many cases, the garment mimics the distinctive costume of the character, encouraging the wearer to pretend to be the character. In others it features an image of the character and/or logo on the undershirt.