Dutch: Toverlokjes
French: Minicouettes
German: Glückssträhnchen
Italian: Ciuffetti
Norwegian: Lykkesvansene (thanks to Else Fjøsne)

Lady LovelyLocks' Pixietails are called:
Pixiebeauty
Pixieshine
Pixiesparkle

Pixietails are little magical creatures that can be just a little bit naughty at times, but are always ready to lend a helping hand. They always talk with "ix" appended to the words, which sounds very cute.

There are a few different subspecies of Pixietails: Lady LovelyLocks' Pixietails have the bodies of bunnies, Maiden FairHair's look like chipmunks/squirrels, and Maiden CurlyCrown's look like birds (these usually have curly tails as well).

The Pixietails that live on the Enchanted Island are known as Sea Magic Pixietails, and they can have the bodies of fish, turtles, seahorses, ducks, ferrets/minks or snails (thanks AK!). Their tails have shorter curls as well as longer waves.

The Flower Ball series has pixietails that look like butterflies and they have glittering strands of hair. (Thanks Angelkomeko for reminding me!)