Thegwyllgi (Welsh pronunciation:[ˈɡwɪɬɡi]; compound noun of eithergwyllt "wild" orgwyll "twilight" +ci "dog"[1]) is a mythicaldog fromWales that appears as a frightfulapparition of amastiff orblack wolf with baleful breath and blazing red eyes.[2] It is the Welsh incarnation of theblack dog figure ofEnglish folklore.
TheGwyllgi are also calledCwn Annwfn orCwnAnnwn (meaning "dogs of the otherworld") and Cwn Cyrff ("corpse dog").[3]
There have been many sighting of this beast in the north east of Wales. Specifically, the Nant y Garth pass located nearLlandegla inDenbighshire. It has even been spotted as far away asMarchwiel inWrexham and as to this day there are still many sightings of this fearsome creature.[4]
InBlood of the Earth, byFaith Hunter, many members of the local cult-like church have been turned into gwyllgi and capture the main character, Nell.
In the Well of Shadows series bySL Harby, gwyllgi play a prominent part in the story of the Songspear, Aristoi.
InThe Beginner's Guide to Necromancy series byHailey Edwards, a gwyllgi named Hood is one of the watchmen who guards the Faraday, a high-end condominium where Linus lives. His friend, Lethe, becomes close friends with the main character. Her brother is the Beta of the pack in Atlanta.