Trotterkopf

Trotterkopf are goblin-like familiars from Pennsylvania Dutch folklore, they are a very obscure creature and thus not found in media outside their native folklore, even within their local folklore they are quite mysterious beings and can easily be mistaken for similar entities, they have their origins in older beliefs in witches, who were often said to communicate with evil spirits or animate creatures to work for them as servants.

History
a Trotterkopf is a type of familiar found in Pennsylvania Dutch folklore and resembles in many ways a goblin - they serve witches and other evil magic-users, traveling by hours of night to do their bidding, sadly not many specifics are known but a great many prayers and rituals seemed to be created specifically to ward off these creatures, showing they were a large part of life for the superstitious.