|Source books||Menzoberranzan boxed set (1992)|
The alhoon (illithilich) first appeared in the second edition for the Forgotten Realms setting in the Menzoberranzan boxed set, in the booklet "Book One: The City" (1992), and reprinted in Monstrous Compendium Annual Volume Three (1996). The creature was further detailed in the Illithiad (1998).
An alhoon is essentially an illithid that chooses to focus on developing arcane abilities in addition to its psionic ones, eventually becoming both undead and a mage. In illithid society, illithids who choose to develop arcane abilities become outcasts and they may eventually transform themselves into powerful undead creatures with formidable psionic and arcane abilities.