Professor Thaddeus

 is an owl pet of Beau. As an NPC, is played by Matthew Mercer.

Appearance
Though more akin to a great horned owl, the owl species that Professor Thaddeus belongs to has adapted to the more temperate region of the Menagerie Coast. The feathers are more lithe, the body is more elongated and thin, the tail feathers are longer, and the beak is sharper.

Personality
Much like his owner, Professor Thaddeus is ill-tempered, aggressive, and disobedient. While he rarely obeys Beau, he appears to respond better to stern commands and swear words.

Beau purchased the owl from Kestriv for 20 gp.

After meditating for ten minutes at the beach, Beau began training her new owl to come to her when she raised her forearm "majestically". After an hour of training, Beau was able to train Professor Thaddeus to come to her, but only after coaxing him with some food (such as a rat or a seagull).

Beau had Professor Thaddeus boarded at the Lavish Chateau during the Mighty Nein's stay in Nicodranas.

After the events on the dockside, when Beau calls out for him onboard the Mist, it is revealed that Professor Thaddeus did not follow Beau and the party and instead remained somewhere in Nicodranas.

Beauregard
Beau respected Professor Thaddeus, his stubborn nature reminding her of her own attitude.

Caduceus Clay
Due to Caduceus's ability to Speak with Animals, Professor Thaddeus had a stronger bond with the firbolg Cleric than his actual owner.

Abilities

 * Flyby: doesn't provoke Attacks of Opportunity when it flies out of an enemy's reach
 * Keen Hearing and Sight: Advantage on Wisdom (Perception) checks that rely on hearing and sight
 * Talons: Melee Weapon attack, +3 to hit, reach 5 ft., one target, Hit: 1d4+2 slashing damage

Trivia

 * The name "Professor Thaddeus" originates from a character that Marisha met during Burning Man: "Professor Thaddeus Bubo", proprietor of the "Single Seat Circus". Burning Man is an annual event in the Black Rock Desert of Nevada that experiments in artistic self-expression and radical community inclusion and cooperation.  Matt, Marisha, and Taliesin are well-known for having attended the event each year since before Critical Role first aired.
 * When Beau asked if the owl would try to eat Jester's new crimson weasel, Kestriv stated there was a reason that the two animals were kept in separate cages. Beau resolved to try and teach the two to become friends.