He is incredibly tall (taller than most, if not all the other people of South Park) and somewhat fat. He wears a blue sweater and brown trousers. Under his sweater is a white shirt. He has orange-red hair, although he seems to be balding. He also has a protruding chin. In "South Park is Gay!" he wore a nearly-unbuttoned red shirt, pink scarf, gold necklace, a belt, and striped white pants.
Thomas has displayed an uncaring attitude. In "Tweek vs. Craig", when Craig told his family about the fight that was going to occur, Craig's father replied with an indifferent, "Oh", not caring in the slightest, which resulted in the whole family giving each other the middle finger. However, he did seem to show some concern for his son in later episodes. For example, he was shown to be really worried about Craig's absence during Pandemic.
In "Magic Bush" he was really supportive of his wife and her privacy.
In "Tweek x Craig" he was happy when he heard Craig was involved in a fight, implying that he encourages Craig's "bad boy" attitude. Later, when he finds out it was a "lover's quarrel with his boyfriend" he's angry and complains about it, stating that homosexuality is something they didn't accept in his times, and even though he recognizes that "maybe it's not so wrong", he doesn't want his son to be gay. Nevertheless, at the end of the episode he supports Craig and tells him that he loves him.
Craig is his 10 year old son. In "Tweek vs. Craig", their interactions do not seem to show that he has an even remotely close bond with Craig. He appears indifferent and uninterested in Craig getting into a fight.
However, he and his wife were visibly upset and were seen crying when they send Craig away, along with the rest of the kids in South Park, in "Child Abduction is Not Funny". In "Pandemic", after Craig goes missing, Thomas and his wife appear to be very worried about Craig and even stick up for him after the other boys' parents call him a bad influence. In "Pandemic 2: The Startling", Thomas and his wife are overjoyed when Craig returns home.
He does not seem to have an incredibly close bond with his wife; in "Tweek vs. Craig" their interactions seem to show only a tenuous relationship between the two. However, they are shown consoling each other in later episodes.
He also has unnamed daughter, but due to a lack of interaction, their relationship remains unknown.
"What did I do wrong, huh? Everyone's so damned happy, but... but why did this have to happen to my son?! What did I do to make my son like this?" - Tweek x Craig
"I can see how much they're both hurting, but... Can't you understand that in my time we just didn't accept this? Maybe it's not so wrong, I, I just don't want it to be my son" - Tweek x Craig
"Son, you need to listen to me. You can't fight being gay. I used to think that being gay was a choice, but, you don't get to decide. Japan picks who they pick, and that's that. I don't understand this stuff. Heck, I didn't even know Don King got raped, but... I do know that if you try and resist it, you make yourself miserable your whole life. Everyone was so proud of you, Ah I was just being selfish. I wanna be proud of you too. I like gay Craig. I love you. Here's a hundred dollars" - Tweek x Craig
- "Tweek vs. Craig" - Appears at home, eating dinner with his family.
- "The Entity" - Seen testing IT out.
- "Here Comes the Neighborhood" - Taunting some of the rich people on the bus as they sit in the front seats.
- "South Park is Gay!" - Appears as one of the most prominent and outspoken metrosexual fathers.
- "Grey Dawn" - Thomas and his wife a prisoners of the AARP.
- "Cartoon Wars Part I" - Thomas buries his son and his wife along with himself in sand.
- "The Losing Edge" - Appears with the other parents cheering the boys on.
- "Pandemic" - Approaches the boys' parents about his son's whereabouts after they go missing.
- "Pandemic 2: The Startling" - Is seen reunited with his son at the end of the episode.
- "It's a Jersey Thing"- Thomas and his wife help fight the Jersey Folk.
- "Jewpacabra" - Seen at the Easter egg hunt.
- "Sarcastaball" - Seen at the PTA meeting with all the other parents.
- "Insecurity" - Seen with the other adult males rallying to get rid of the UPS delivery driver.
- "A Scause For Applause" - Seen in the background while Jesus Christ gives his speech.
- "The Magic Bush" - He tries to defend his wife against mockery over her "bush", but, in trying to do so, ends up being part of the mocking.
- "Tweek x Craig" - He gets upset when he finds out his son is "gay," but grows to accept it towards the end of the episode.