Kobold

Tom's home has a kobold infestation.

Let go the apples, boy / or the ‘Jump-on’ will get you. / The ‘Jump-on’ is a strong kobold / who brutally punishes thieves.

1904, Andrew Lang (collector), author and translator not identified, The Mermaid and the Boy, The Brown Fairy Book, page 176, At this point a cock crew, and the youth jumped up hastily saying : 'Of course I shall ride with the king to the war, and if I do not return, take your violin every evening to the seashore and play on it, so that the very sea-kobolds who live at the bottom of the ocean may hear it and come to you.'

Movers, in the first chapter of his Phönizier, says that that group of deities called Dactyls, Cabiri, Corybantes, and Cyclopes, were similar to those old Germanic divinities now known as Kobolds.

a. 1867, George MacDonald, The Shadows, 2000 [1980], The Golden Key and Other Stories, page 96, The king had seen all kinds of gnomes, goblins, and kobolds at his coronation; […] .

On the other hand, the kobolds, brownies, and other household sprites who are not merely benign, but helpful, if well treated; the elf-maids who marry mortals, the swan-maidens, and the like, bear the stamp of Teutonic fancy.

Among the nonhuman creatures that peopled rural Europe in the Middle Ages — the fairies, elves, dwarfs, trolls, and kobolds — there were beneficent female spirits who patronized those households that treated them well.

In Germany also the kobolds are rather troublesome than otherwise, to the miners, taking pleasure in frustrating their objects, and rendering their toil unfruitful.

There were also various trolls like great smiling badgers, brownies darting about laughing, dwarves with large gray heads, sensuous mermaids, stony kobolds, green gnomes, sirens and many elves, who were busy purifying the sacred hilltop in a mythological cooperation marvelous to the soul's perception.