Witches' butter

Witches' butter (or Witch's butter) may refer to:


 * Exidia nigricans, a black, gelatinous fungus
 * Exidia glandulosa, a black, gelatinous fungus
 * Tremella mesenterica, a yellow, gelatinous fungus
 * Dacrymyces, a jelly fungus often confused with Tremella
 * Nostoc, a genus of gelatinous cyanobacteria