A kelpie lets weary travellers ride on it's back and then it drags them to the bottom of lochs to devour them. Sometimes they are said to change into beautiful maidens.
Kelpies used to be a six in the Brownie Guides. The six badge sort of looked like a stick man dancing and wearing a beret with a feather in it. My sister was seconder of the Kelpies when she was a Brownie.