Needlings.

There is an old saying, "If you have a Needling, you'll want for nothing else".
This is true. If a Needling enters into your life (usually they become attached to you if you perform some sort of kindness for them) there is nothing it won't do for  you. It will carry all your stuff, it will make you food, it'll look after your horse and put up your bedding for the night. It will care for you when you're sick, and constantly wake you up in the night to check if you're okay. It will continually ask you if you need anything and will not stop bothering you until it is satisfied you have everything you want. Needlings are never satisfied. In extreme cases they can become possessive of you and will attack anything or anyone else that tries to help you.They are, frankly, awful shits.
And you can't get rid of them. If you kill it, a new one will find you and carry on where the old left off. The only real way to stop them is to kill their queen.

 

Queen Needlings (or Queenlings) are giant versions of Needlings that live deep underground in vast caverns. All Needlings love their Queen and those that are not chosen to take constant care of her are sent out into the world to commit their acts of caring upon others. The link between Queenling and Needling remains strong, and upon their Queens death, the Needling will curl up and die.

Needling
HD: 2, HP: 8 , AC: 0 , Damage: 1d4 (biting damage).
If they're in defence of their Queen there will be 2d20 of them attacking.

Queenling
HD: 10, HP: 53, AC: 4, Damage: 2d8 (fists).
Special: The Queen will squirt disgusting acidic milk from one of her three breasts doing 2d6 damage, plus another 1d6 per round if they don't wash it off.