ADDANC
Welsh Folklore
The name of a dwarf or water spirit that inhabited Lake Llyon in Wales. According to the region of the narrator and the SPIRITS activities, he was known by different names: ABAC, AFANC, and AVANC. This DWARF or DEMON was considered to be responsible for terrible flooding by making the surrounding waters of the lake overflow into the surrounding country. He was eventually dragged from his abode by the oxen of HU GADARN and, some say, killed by PEREDUR.
SOURCE: Spirits, Fairies, Leprechauns, and Goblins Encyclopedia