Dr. Deaton

The Veterinarian (Dr. Deaton) is a recurring character in Teen Wolf and is played Seth Gilliam. He works at the Beacon Hills Animal Clinic where he is Scott McCall’s boss. He is aware of the existence of werewolves and seems to know quite a bit about them.

Name
His name is only mentioned once in Season 1, by Stiles in Night School. While it apparently appeared as Dr. Deaton on the call sheets for the production it appears in no official public sources that could be considered official canon for the show. It is mentioned in the Teen Wolf webcomic at MTV.com, but events and characters in that publication do not match what happened on the actual show and so are not, at this time, considered official canon.

Season 1
Sheriff Stilinski has sought out his help and advice on two occasions in the ongoing investigation of recent animal attacks. On the second time, he is shown to be very nervous and tries to get him to leave.

In Heart Monitor, Derek Hale becomes convinced the Veterinarian is The Alpha after the doctor lies about a dead deer found with The Spiral burned into its side. Derek attacks and knocks the man unconscious, ties him up and dumps him into the back seat of his car.

The Vet disappears just before the Alpha appeared at the end of Heart Monitor but reappears seemingly unharmed at the end of Night School. Scott asks him how he got away but he is vague in his response.

In Co-Captain he finds Scott and takes him to the Animal Clinic to remove the bullet. He says treating animals is only 90% of his work and suggests that he has treated werewolves before.

In Formality, it becomes clear he has enough knowledge about werewolves to ward off attack. Peter Hale is unable to cross the bar into the back of his clinic. The bar is made of “Mountain Ash”. This angers Peter who smashes a chair against the wall but the doctor doesn't flinch.