Coyote

Coyotes almost always travel in packs like their wolf cousins. They have sharp teeth and will frequently knock a target over, then attack the head.

They are a bit stronger than the dog but weaker than the wolf.

Wild Mutant Coyotes
Wild Mutant Coyotes are dog seen in Carbon,Texas.

Imagine a large, wolf sized Coyote trying to bite your face off. Now imagine a pack of them. Sounds like fun? Then you'll love these scavengers! They hunt in groups, and they're always looking for a little meal to tide them over until nighttime. You just happen to be the next thing on the menu...

Fallout: New Vegas
Coyotes return in New Vegas. They will not always attack you, even though they may show up as hostile on your radar.

Appearances
The coyotes appear in Fallout and Fallout: New Vegas. They were also going to appear in the canceled Fallout: Brotherhood of Steel 2.