Muggles' Guide to Harry Potter/Magic/Gnome

Overview
The Gnome is a common garden pest found throughout North America and northern Europe. Its body is out of proportion, its head is too big, it has sharp claws and bony feet. It grows up to about 12 inches tall.

Extended Description
The most popular form of removing a gnome from a garden is to pick it up, spin it around until it is dizzy, and then throw it over a garden wall. According to Gilderoy Lockhart, this causes the gnome to become disoriented and he cannot find his way back; however, it appears that their disorientation is only temporary, as Harry sees the Weasley's gnomes making their way back to the garden only hours after using this technique to remove them.

At the wedding in Harry Potter and the Deathly Hallows, Luna Lovegood is very pleased that a Weasley gnome bit her finger. Her father, Xenophilius, explains that gnome saliva has many beneficial properties. This is doubtful as the Lovegoods hold many peculiar beliefs about magical creatures.

It may be possible to teach a gnome to speak English, as Ron says at one point that their gnomes "do know quite a lot of excellent swear words," going on to speculate that Fred and George taught them those.

Analysis
The appearance in Harry Potter and the Chamber of Secrets could be seen as a first intimation that Gilderoy Lockhart is not the wizard he claims to be. The technique for eliminating garden gnomes comes straight out of Gilderoy Lockhart's Guide to Garden Pests, and appears to be effective, as the gnomes, once dug out of the garden and flung into the neighbouring field, march away in the wrong direction. But by sunset the same day, when Harry looks out of Ron's window, the gnomes are already sneaking back into the garden.

Having created the gnomes and infested the Weasley's garden with them, the author perforce must make them reappear in the Weasley's garden whenever we see it. To that end, Crookshanks the cat chases one into a boot in one scene, and one is charmed to be the angel on top of the Weasley's Christmas tree in another scene.