Growing up, Cletus, developed a loving relationship with his mother, whom he addresses as 'Maw'. He married a close relative, Brandine Del Roy. He has several hobbies which include whittling "piney babies" for children, searching for roadkill, digging through garbage, and spending time with everyone in his family. He admits his favourite food is fresh skunk and raccoon, and had a "smell-hound" named Geech.
Cletus's unusually fancy signature
Cletus suffered from some sort of illness caused by drinking mercury out of a thermometer, which badly affected his memory, but for which, of course, he never sought medical attention. He whittles what he observes into wood with a penknife. Chief Wiggum was able to track down Bart and Gina after they escaped from jail through Cletus' wood carving of them. Cletus also possesses a form of precognitive vision through whittling. He predicted that Chief Wiggum would be mauled by a bear later in that episode.
Cletus and Brandine have a basically happy relationship but often bicker. Cletus once showed more love to a pig than Brandine. Once, she wielded a shotgun at him for giving the pig "a day of beauty and make-up" instead of herself. Cletus and Brandine were once rejected from coming to Lenny's party after they are both afraid to use the "uppity box" (an elevator).
Cletus works as a fifth generation dirt farmer. He also owns a successful chain of moonshine stills, and was delighted when it was decided that his drink would be used to flavor the latest version of Southern Cracker. He and Brandine operate a vegetable shack near the Kwik-E-Mart. He is currently in the process of opening a family business that sells miscellaneous animal parts. Cletus took advantage of the money his children were making and used it to his own personal satisfaction.
During Trappuccino, Cletus successfully distracted Russ Cargill while the town tried to escape through a hole in the top of the dome by rope. However, Homer came down the rope at the same time after climbing up the Dome, knocking everyone, including Cletus, off the rope. Dr. Nick Riviera was the only fatality.
Cletus plays the washboard in the Spuckler Family Band.
Cletus dresses in a sleeveless tattered white shirt and blue pants. He also has a snake tattoo on his arm. Snake has the same tattoo.
Cletus has an ongoing relationship with Brandine, who is generally represented as his wife, although the nature of their exact relationship is somewhat vague. It is often implied that the two are siblings. At an auto racing event, Brandine remarks "Dang, Cletus! Why'd you have to park so close to my parents?" to which Cletus responds, "Now honey, they's mah parents too!" however, he may mean that they are his in-laws. (This plays into the stereotype that incest is prevalent among hillbillies).
Homer, who was ordained over the Internet as a minister, was once preparing to marry Cletus and Brandine. Looking at a form, he asked "Wait a minute... are you two brother and sister?" Brandine replied, "We's all kindsa thangs." To complicate the issue further, Brandine remarked to Cletus "Yer tha best husband – and son – I've ever had." If all this is correct, it is to be assumed that "Maw" is his stepmother and Brandine is his natural mother, his father being Brandine's father making him her half-brother and son. Further confusing matters, one of Cletus' sons create a hand-drawn family tree. According to this diagram, Brandine is the child of Cletus and an alien. Cletus and Brandine have thirty-nine children, which include a sheep and a walking hot dog.
At some point, he had a relationship with Edna Krabappel.
Cletus seems to be the father of a large number of children, by some accounts as many as 44. When he presents Marge with 300 coupons for free pretzels from her pretzel business, he calls out to Tiffany, Heather (twice), Cody, Dylan, Dermot, Jacob, Jordan, Taylor, Brittany, Wesley, Rumer, Scout, Cassidy, Zoe, Chloe, Max, Hunter, Kendall, Caitlin, Noah, Sasha, Morgan, Kyra, Ian, Lauren, Qbert, and Phil. Cletus and Brandine also have a daughter, Condoleezza Marie, who was somehow switched with a bag of sugar that Homer was carrying as part of a parenting exercise, and a daughter named Rubella Scabies, whose middle name was inspired by a word spelled by Lisa in her audition for the annual spelling bee. They have another daughter, Gummy Sue. Lisa encounters Cletus gathering up roadkill for a hillbilly wedding feast. In the short dialogue that ensues it is implied that Brandine is giving birth to yet another child in the truck's cab. The children's names seem to mock the pretentiousness that celebrities have in giving their own children "cute", unorthodox, or non-traditional names, as well as the propensity of the white-trash and the uneducated to copy this trend.
Lisa once tutored seven of the Spuckler children, named Birthday, Crystal Meth, Dubya, Incest, International Harvester, Jitney and Whitney. However, Brandine reveals that Cletus is the father of only two of these children (casting doubt on the paternity of the other children of the Spuckler household). Brandine was once seen to give birth in a car, apparently with very little pain, and asking Cletus to cut the "umbrellical cord". After one of his children, Carl, is accused by Homer of cheating at soccer, Cletus says of his children, "I have sired a dumb-dumb, a mush-head, a whatsit, a dogboy, and something with a human face and fish body what we called Kevin. But my young'uns is not dirty players!" 
One of their daughters, Mary Wrestlemania Spuckler, who is supposed to wed Bart.  Cletus mentions that they "name all their kids after what they think is gonna happen to them. Ain't that right, 'Stabbed In Jail'?" to which Stabbed In Jail Spuckler (who is seen sharpening a wooden stick) replies, "We'll see who stabs who."
Brandine refers to him as Cletus Del Roy Spuckler, implying that Del Roy is his middle name and Spuckler is his last name. Cletus signs this as his name in surprisingly elegant cursive to Marge's petition to ban sugar from Springfield.