Biter

Biter is a unique skeever in the elder scrolls Skyrim.

He is aquired by the Dragonborn if the player has the Hearthfire DLC and an adopted child. The child will come home saying that Biter has been following him around all day and consiquently if they can keep him. If the Dragonborn agrees to the skeever living in their home, he will do so.

You are unable to interact in any was with Biter and he will usually be found pacing the childs room if the child is not in the house. When the child comes home Biter will run up to the door to greet them, much like a dog.

If Biter is killed in front of the child they will not care, and only resond to the fact that you have unsheated a weapon.