In their first appearance "Gnomes", it is revealed that Richard and Mrs. Tweak are the joint owners of Tweek Bros. Coffeehouse family coffee shop, which only stays open due to being the only coffee shop in town. However, when Harbucks (a parody of Starbucks) plans to open a shop in South Park, Richard grows concerned that they'll be run out of business.
Upon discovering that their son Tweek and the Boys need to write a current event report in front of the Town Council (in order to prove to them that Mr. Garrison is a competent teacher), Mr. Tweak decides to use the boys to push his agenda regarding Hardbucks. He proceeds to write a long-winded paper about how big business is destroying small family-owned business. The speech works, causing the town to turn against Harbucks and try to push through a legal proposition to outlaw Harbucks.
While Richard is thrilled at having used the kids to push his beliefs, Mrs. Tweak is disgusted by her husband's behavior, wanting nothing more to do with it. When the boys later discover from the Underpants Gnomes that big corporations are good, she joins the boys and explains to the town that Harbucks got to where it was by being the best. Richard, realizing she is right, makes amends with the owner of Harbucks, who asks him to run the South Park branch.
When he next appears in "Tweek vs. Craig", Richard tells Tweek that when he was in high school, all the young men were after Mrs. Tweak, but she only had eyes for Richard. One day, a football player who went by the name "Quib" wanted her, and he challenged Richard to a fight. Richard doesn't say what happened after that, other than that Quib moved away.
Their next major appearance was in South Park is Gay!, in which the men and boys of South Park begin obsessing over the new Metrosexuality fad caused by Queer Eye for the Straight Guy. At first the wives love the new versions of their husbands and sons, but soon realize that its not as good as they initially though. When the men and boys become too wimpy and shallow, the wives realize that they preferred their husbands been strong men. The wives then proceed to go to New York, where they then kill the Queer Eye guys, who are revealed to be Crab People.
Richard wears a burgundy-red sweater, and grayish-blue jeans. His hair is short, curly, and dark brown, with a rather long, pointed nose. He talks calmly which is completely opposite of jittery Tweek. He often gets lost in his own little-world where he repeats cliche metaphors about how good something is.
Judging from the events of "Gnomes", he appears to be manipulative, exploiting his son and the boys in order to help run Harbucks out of town. Generally, his relaxed nature serves as a contrast to his son Tweek.
Richard and Mrs. Tweak have a son, whom they have named after the family name. Unlike either of his parents, Tweek has blond hair. This could mean that he is a throwback to an older ancestor. Richard has been shown to attempt strong male-bonding with his son. Whenever Tweek is spazzing out over something, Richard will try his best to calm him down, usually by giving him coffee. Both parents seem unaware of the fact that caffeine is what causes Tweek's paranoia and hyperactivity in the first place. Richard apparently pays for therapy for his son, though it doesn't seem to have worked. Tweek alleges, however, that his parents "never help" in "Tweek vs. Craig" and bangs his head into the table, with his parents not noticing. In "Child Abduction is Not Funny", it is shown that despite sometimes using abusive methods towards their son for his own safety, they care deeply for him like any normal parents and are only trying to protect him.
Richard is married to Mrs. Tweak. They are shown to have a good relationship, however, in "Gnomes", Richard seemed oblivious to his wife's objection to what he was doing.
- "Gnomes"- Debut Appearance. Helps his son and The Boys write their report about corporate take overs.
- "Tweek vs. Craig"- Tells Tweek an unhelpful story.
- "Osama Bin Laden Has Farty Pants" - Seen in the background.
- "Red Hot Catholic Love" - Becomes an atheist along with everyone else in town.
- "Free Hat" - Tells his son to find his center.
- "Child Abduction is Not Funny" - Attempts to prevent his son from being abducted.
- "The Death Camp of Tolerance"- Seen at the Meuseum of Tolerance. Unknown whether he picked up Tweek earlier at the camp or not, as Tweek isn't seen working at the camp, despite being seen when the children first arrive.
- "South Park is Gay!" - Seen going along with the metro-sexual fad.
- "It's Christmas in Canada" - Seen in the crowd of people at the Christmas tree lighting in South Park.
- "The Losing Edge" - Seen at the baseball cheering on his son's team.
- "Mystery of the Urinal Deuce" - Seen in the background.
- "Smug Alert!" - Buys a hi-rebid car along with everyone else in South Park.
- "201" - Seen at his coffee shop, when Mecha-Streisand.
- "Sarcastaball" - Seen at the PTA meeting with all the other parents.
- "Informative Murder Porn" - After their murder porn is is blocked, he, along with the other parents, learns to play MINECRAFT in order to get past the Children's block. He is referenced to have bypassed it however. Later helps the other parents get their revenge by ruining the children's MINECRAFT experiences.
- "Stunning and Brave" - Seen when PC Principal is announced as the new principal.
- "The City Part of Town" - Seen in a town meeting.
- "You're Not Yelping"- Seen in the Mayor's office.
- "Tweek x Craig"- Proud about his son's "homosexuality". Later is distraught that his son and Craig "broke up"
- "Naughty Ninjas"- Seen in the protest against the police.
- "Skank Hunt" - Seen at the school assembly.
- "Not Funny" - Seen at Mr. Slave's Residence.
- "The End of Serialization as We Know It" - Seen with his family at his residence.
- "Franchise Prequel" - Asks Mark Zuckerberg to leave the Tweak Residence as he goes through their refrigerator.
- "Dead Kids"- Seen when Sharon calls the other parents together to speak about school shootings. Later seen when Randy sings.
- "The Scoots" - Frantically gives out treats to trick or treaters.
- "Nobody Got Cereal? - Seen in front of Park County Courthouse, waiting for Stan's verdict on the negotiation with ManBearPig.
- "Unfulfilled" - Gets a new job at the Amazon Fulfillment Center, due to Tweek Bros. Coffeehouse's negative incomes.