Coblynau are mythical gnome-like creatures that are said to haunt the mines and quarries of Wales. They are said to be half a yard (1.5 ft) tall, and very ugly. Like Knockers, they are dressed in miniature mining outfits. They work constantly but never finish their task, and are said to be able to cause rockslides. The word Coblynau is derived from the English Goblin ultimately derived from a Germanic source akin to the German Kobold, via the French Gobelin.
Coblynau are mentioned in the Constantine episode "The Darkness Beneath", but the description of the creatures given is closer to knockers.
When she stopped talking to me
I knew that she would create a problem
And after five seconds flat
She came at me just like a goblin
Months passed and things calmed down
So me and her went on a plain date
I said you’re walking cliché
But she said it’s just you and me, babe
Okay
So it’s just us walking through town
And we go in the liquor store
Buying two beers
Spying a cat in the window of the bar next door
Then she was cursing at me
And pointing at het witches cauldron
Grabbed me, she got in my face