I don't know exactly. Undead. Infected. Hell, you could even go as far to call them zombies, but I know that's not really a popular choice of description these days. But they didn't fit the criteria of your standard rotting humans.

Thought I could take them out with a flashlight, but a quick beam of light on whatever they were and I bolted for safety. It seemed to have multiple heads; some moving, some hanging down. That was enough for me.