Derek doesn't react when Dean slices clean through the neck of the creature nearest him. Once you slice through your uncle's throat with your own claws, that kind of shit doesn't really faze you anymore.

One of them screeches and throws herself at Derek, but he reaches out to grab her by the throat, claws digging in. She's much stronger than a human, but no match for Derek. He holds her at bay easily, not even flinching when she tears at the skin of his forearm with her nails and hisses at him. He looks at her odd fangs curiously before casting his gaze back to Dean, who seems to be holding his own for now. "What are these and we are we killing them?"