Dog part that escaped the flamethrower was burned up later on during the camp blaze. It could have buried itself though but just going off of what Carpenter said it’s either Mac, Childs, or neither.
“The closest thing to a definitive answer may have come from cinematographer Dean Cundey, who said he and Carpenter used eye light to show who was human and who wasn't. If that's true, and you look closely, it's more likely the thing is Childs than MacReady.”
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