Den of Geek:
"This review contains spoilers"
The newest monster from the bestiary to hit Beacon Hills is a pretty disturbing, troublesome critter. No one really knows what it is there for, except for the local veterinarian. As it turns out, Dr. Alan (or Allen) Deaton (Seth Gilliam) is more than just a vet. He's the key to pretty much every mystery. The first season established that he knows all about werewolves, and now it turns out that he also has some sort of past history with the Argents as well. While he's not exactly clueless about the lizard monster that's stalking Beacon Hills, he doesn't know what it is.