Ackerman wore a "Hunchbackerman of Notre Dame" costume to the 3rd Worldcon (1941), which included a mask designed and created by Ray Harryhausen, but soon stopped wearing costumes to conventions. Douglas wore an Akka costume (from A. Merritt's novel "The Moon Pool"), the mask again made by Harryhausen, to the 3rd Worldcon and a Snake Mother costume (another Merritt costume, from "The Snake Mother") to the 4th Worldcon (1946). Terminology was yet unsettled; the 1944 edition of Jack Speer's "Fancyclopedia" used the term costume party.