This is what's written in Arthur Spiderwick's Field Guide to the Fantastical World Around You about Knockers.
Deep Cavern Knocker
Knockers (Family: Cavernahabentidae)[]
Also known as kobolds, these enigmatic creatures most commonly live in mines, mimicking the sounds of miners by tapping against the rock walls. It is said they do their own mining at night when all the humans have departed, but since they do not appear to craft metal, it is unclear what they are seeking under the ground.
Knockers are valued because they will warn miners of impending disaster (like collapses) by pounding on the walls. Sometimes the pounding sounds like it's coming from all directions, alluding to a large number of creatures, but this may merely be a trick of the acoustics.
Knockers cannot abide whistling and swearing. They will cause small showers of stones to fall on anyone performing these actions or in other ways disrespecting them.
Outside of mines, knockers can be found in wells, caves, and sometimes even in basements.
- Deep Cavern Knocker (Amicus auritus)
Additional facts[]
A Knockers' translucent skin is covered in fine hairs like a peach.
Their ears can move independently of one another, just like the cat's or horse's.
Knockers are related to Goblins and Hobgoblins, and just like them, Knockers tend to collect Human artifacts and become fascinated by them.
Known Knockers[]
One Knocker lived in Old Quarry. When the three Grace children escaped from their, they received help of the little Kobold.
In the video game console adaption of the film, Simon can find a Knocker in the goblin camp, which will upgrade his gobstones to explode on impact. Another knocker can be found in the tunnels when Simon throws a gobstone at a crystal to lure out the cave knocker. This creature will give Simon some more gobstones upon interaction.
Behind the scenes[]
In German folklore, a Kobold is a Dwarf-like being who knocks on the cavern walls of mines, either pointing out a rich lode or warning of collapses and choke damp. Around the British Isles, a similar creature is known as a Knocker. Also, in Scandinavia, there is a Faerie called a Gruvrå ("Mine Watcher"), Gruvfru ("Mine Lady") or Bergrå ("Mountain Watcher") who has adopted the same function. Most commonly, she appears as a beautiful woman in a grey dress, but can also look like an ugly witch, a bearded little man {Dwarf}, a bat or some other animal.
Appearances[]
