The Cultists in Q: The Serpent God really fucking goofed.
Quetzalcoatl, being one of the more benign deities of the Aztec pantheon, discouraged human sacrifice. This leads to either two possible interpretations. Either the cult made the mistake of trying to summon him with a human sacrifice and ended up corrupting him because of it (turning a normal, nice god into a man-eating abomination) or they ended up summoning a different god altogether, probably the much less benevolent Yig.
The creatures in "Beast Of Bray Road" really were government made.
If you follow normal evolution, a wolf or bear-like creature evolving to walk fully on it's hind legs is impossible. This leads to the interpretation that they were the result of a government (perhaps FBI or CIA) "super soldier" program, which were used to attack the militia base. However, after achieving this, they escaped, and the military are currently trying (and, evidently, failing) to recapture them.
- Or it's a more traditional werewolf, as opposed to the other one in S2.
Matt in Wendigo was still fully human.
There is a syndrome called "Wendigo psychosis" in which a human thinks that he is going to turn into a Wendigo and cannabalise the people around him. Matt may have developed this psychosis in the episode. My reasoning for this is:
1. It is never stated in the episode that he is entirely supernatural.
2. It makes the episode creepier.
- I think his teeth would disagree with you there.
- He could have used a knife to file them himself. It certainly would be appropriate for his growing psychosis.