What is "zuggtmoy"

In the Dungeons & Dragons fantasy role-playing game, Zuggtmoy or Tsuggtmoy is the Demon Queen of Fungi. Her symbol is a jawless human skull with fungi blooming from within, though some of her false cults use other symbols. For example, her cult in the Temple of Elemental Evil used the symbol of the Elder Elemental Eye.

Zuggtmoy is the "dread and fell ruler of the 222nd ghastly plane of the Abyss."