Afanc: a lake monster (exact lake varies by story)
Coblynau: little people and mine spirits
Coraniaid: a mysterious race of beings who plagued the Island of Britain
Cwn Annwn: hunting dogs of the Otherworld
Cyhyraeth: death spirit
Y Diawl: The Devil*
Dreigiau: Dragons (the most famous being Y Ddraig Goch)
Gwyllgi: a large black dog that haunts lonely roads.
Gwyllion: a kind of spirit
Llamhigyn y Dwr: a frog-bat-lizard hybrid
Morgens: water spirits
Pwca: shapeshifting animal spirit
Tylwyth Teg: the fairy folk, inhabitants of the Otherworld
* The devil was said to have built various bridges in Wales (including Devil’s Bridge, Ceredigion), and to appear to sinners in the form of a horned, black-faced shepherd leading a pack of dogs. Sometimes associated with the bobtailed black sow known as Yr Hwch Ddu Gwta.