Crevan Espane aep Caomhan Macha, also known as Avallac'h, is an elf and Aen Saevherne who travels between the worlds of the Aen Elle and Aen Seidhe. He meets Geralt and tells the witcher about a prophecy connected with Ciri. He was nicknamed 'Fox' by the unicorns.

Lara Dorren was originally intended to marry him, before she fell in love with Cregennan of Lod.

He appears in the novels Wieża Jaskółki (English: The Swallow's Tower) and Pani Jeziora (English: The Lady of the Lake) and is mentioned briefly in the Traveler's diary in the Side Effects premium module.