Thomas, (real name Nikolai), was a recurring character in Regular Show. He made his debut in the Season 4 premiere "Exit 9B".

Thomas is a goat with tan fur and hair, grey horns on top of his head, and a small brown beard on his chin, standing 5'9". While undercover as an intern, he usually wore a black t-shirt, tan pants and red and white sneakers. As a spy, he has worn a ninja outfit and a black sweater.

Thomas can be viewed as the "straight-man" of the Park staff; he is usually seen tagging along with the gang on their outings and occasionally during staff meetings.

He is one of the more laid-back members of the Park. He is known for usually being oblivious towards any negative comments directed towards him, and often doesn't react to these, such as a usual running gag of being reproved by his park employees, as well as Rigby's criticisms towards his scary story everyone thought was terrible in "Terror Tales of the Park III." He also provides advice, usually to Mordecai or Rigby, albeit sometimes unhelpful. ("Wall Buddy", "I Like You Hi")

In actuality, his intern personality was just mask for his undercover mission. Being raised in as a Russian spy, he only carries out their orders, even when he receives bad treatment from his superior, Romanoff, and his ally turned enemy, Natalia. That is, until he reminisced the days of his time at the Park, such as being praised by the Park workers for saving the Park, and being treated nicely when spending time with them. Revealing his current loyalty belongs to the Park, as seen that he did care for them due to their kindness to him during his act as an intern. Despite following his mission, he decides that killing them and destroying the Park are not a part of something he signed up for.

He is portrayed by Roger Craig Smith who also voices Sonic the Hedgehog.