Envelope An envelope is a paper package used for the delivery of letters by mail. Superman filled an envelope with mushroom spores, and when he found Raven's Island in the Sky, he sprinkled the spores on the island, which nullified the anti-gravity holding up the island. References ↑ As seen in The Menace of the White Dwarf. ↑ As seen in The Menace of the White Dwarf. External Link Envelope at Wikipedia Retrieved from "https://superfriends.fandom.com/wiki/Envelope?oldid=50823" Categories: Paper Community content is available under CC-BY-SA unless otherwise noted.