A small (maximum height 8 inches) insect-eating tree-dweller with long sharp fingers (two on each hand), brown eyes, and a general appearance of a flat-faced little stickman made of bark and twigs, which serves well as camouflage in its native habitat.
Found in western England, southern Germany, and Scandinavia, a bowtruckle serves as tree-guardian for its home tree, which is usually a tree whose wood is of wand quality. The twiglike fingers of the bowtruckle appear to be primarily an adaptation like that of a woodpecker’s beak, allowing it to more effectively dig out its preferred food of wood lice from its home tree, but they also serve as an effective weapon against the eyes of an opponent. Although ordinarily peaceful, a bowtruckle will attack a human if provoked (which includes perceived assaults upon the bowtruckle’s tree as well as the bowtruckle itself). A witch or wizard seeking to take leaves or wood from a bowtruckle-inhabited tree should offer woodlice or fairy eggs to the bowtruckle to placate and distract it.
Newt Scamander keeps a bowtruckle named Pickett in his pocket (FB/f).
"bow" several English senses, but the obsolete Scottish dialect sense traces back to much older words meaning "dwelling", while some senses come from the same root as the English word "bough", meaning the limb of a tree + "truckle" Eng. to take a subordinate position