He may be encountered if the Dragonborn has adopted a male child. The child will come home saying that Biter has been following him around all day and asks if he can keep him. If the Dragonborn agrees to the skeever living in their home, he will do so. Biter is however a bit smaller than the average skeever.
There are no available interactions with Biter and he will usually be found pacing the child's 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 would. Killing Biter will seriously affect the Dragonborn's relationship with the child that adopted it; however, he will not flee or become aggressive if this is done.