Warg

Wolves that are more than wolves, running in a pack that behaves like one animal with eight bodies. They flank without signalling, break off without hesitating and reform without a sound, and hunters who have watched it happen describe the pack turning as though a single thing turned. In the old tongue the word for one of them is the same word used for an outlaw - a man put outside the law, who may be killed by anyone without penalty. Unlike the ordinary word for wolf, it is not found in recorded personal names, a contrast consistent with how thoroughly the sense had soured. In practice they take horses out of a picket line and are gone before the shouting starts.

Bite: piercing, melee 5 ft, +3 to hit, 2d6+2. Pack Turn: while two or more wargs can see each other, all of them attack with Advantage against any creature already engaged with another warg. They coordinate without any visible signal and cannot be baited apart.

One Mind: they share what any one of them sees. Ambush, invisibility and flanking do not work twice. Take the Horses: given the choice between an armed party and their picketed animals, they take the animals and leave, every time. A party that hobbles its horses close and stands over them has chosen a much harder fight.