Although highly suspicious of the government and of other people, Dale is unaware (although everyone else knows, except for his son Joseph) that his wife Nancy has had an affair with John Redcorn for nearly 15 years, and that Redcorn is Joseph's biological father. This is apparently due in part to his blinding love for Nancy, his incredible naivete, and the fact that he for some time believed John Redcorn to be gay. A recurring gag early on in the series was that whenever Dale would make a comment about being Joseph's father, John Redcorn would show up.
Dale is an accomplished musician, with the electronic keyboard as his principal instrument. His resume includes a stint with the Propaniacs, Big Mountain Fudgecake, and the Dale Gribble Bluegrass Experience.
When the chemicals he used to kill roaches forced Dale to briefly give up his job, he took a position as a corporate hatchet-man and was spectacularly good at firing people, but his action to deal with a roach infestation at that job led him to return to extermination for good. Dale’s favorite TV shows are Sanford and Son and What’s Happening!! He enjoys drinking Alamo Beer with Hank, Bill and Boomhauer. Dale is an avid smoker of Manitoba brand cigarettes, perhaps a parody of Marlboro cigarettes, and also drinks Mountain Dew. In one episode, Dale instructs a boy, who is receiving his kidney, to give his kidney a can of Mountain Dew once a week. He further explains that his kidney likes it ("Dale Be Not Proud"). He also stockpiled barrels of Mountain Dew in preparation for Y2K in the episode "Hillennium".
Dale is Paranoid, and is likely to have Schizophrenia even though he has not been formally diagnosed. Perhaps owing to the research he has conducted as a conspiracy theorist, Dale has a thorough knowledge of the workings of the American government, legal system and bureaucracy. He has used this knowledge to assist his friends, both to help Hank with problems related to renewing his driver’s license, and to help John Redcorn with his land claim and lawsuit against the American government. Ironically, Dale's help for Hank in that instance came about after he realized the Warren Commission report was accurate and became obnoxiously patriotic, to the point of painting a huge American flag on Hank's house and trying to turn Hank in to the Department of Homeland Security after he tried to remove it.
Dale stands 5 feet 10 inches, and can bench press 35 pounds. He shares a birthday with Van Cliburn (July 12). He is almost never seen without his signature cap and sunglasses, he even wears his sunglasses indoors at all times.
He often gets caught up in his (often far fetched and extreme) conspiracy theories, which can sometimes cause him to be very selfish or double-cross his friends (particularly Hank), although in the end he usually sees sense and comes to the aid of his friends. His schemes also tend to run out of steam or collapse; he bought a low-power radio transmitter, and launched his own talk station "serving the tri-house area!" Art Bell-style, but soon ran out of things to talk about on the air. (He later sold the transmitter to a group of Mexicans.)
His trademark line is "She-she-sshhaa," usually heard too fast to phonetically understand, and he says it whenever he is impressed with himself carrying out a plan, or when springing a sudden move. He also exclaims “Wingo!” when excited and “That’s a Gribble of an idea!” when someone thinks of a solution to his problems. He's also known for exclaiming "S'go, s'go!" (a combination of "Let's go") when he's excited and wants to leave quickly and "G'h!" when he is startled or learns something that feeds into his paranoid nature.
In the episode "Tankin' it to the Streets", Dale claims to have completed a Russian correspondence course and can speak the language, though his application of this in handling an Abrams M1A2 tank isn't exactly flawless.
Dale reveals that he doesn’t know what to do with his hands and is consequently a chain smoker (“Of Mice and Little Green Men”). This is also proved when he runs back for his cigarettes, despite the fact that a bomb he created is armed. He once attempted to quit smoking and switched to chewing tobacco, but when his wife prohibited spitting in their house, he started spitting into newspaper and inhaling the fumes. When that was killing him, Boomhauer lit the newspaper and Dale crowned him a genius. Dale also once reacted to a cigarette being taken out of his mouth by screeching “My oral fixation!” (“Torch Song Hillogy”). Dale has been smoking since the 3rd grade (with the same brand). This could be traced back to the fact that in elementary school Dale had social acceptance issues.
In the episode, "Peggy’s Gone to Pots," the original owner of Dale's stolen alias paid him a visit, and asked him to sign some paperwork so that Rusty could get on with his life. Apparently, Rusty Shackleford is the name of a third grade classmate of Dale's who Dale thought was dead, but in fact simply moved away. Dale has claimed to have the birth certificate of a child who died in 1953 with the name Rusty Shackleford. It is not known whether this document is real or fake. The neighborhood block charter is the only document he has ever signed with his real name; he refuses to sign any document authorized by a government official. When he speaks, he speaks slowly and hesitates between words, except when excited.
Dale also bears a resemblance to William S. Burroughs. Johnny Hardwick has stated in an interview that the voice he uses for the character is essentially a “really lousy” impression of Burroughs. In the fifth season episode “The Exterminator”, Dale took a job in an office and was forced to shed his hat and dark glasses and don the type of generic grey suit that was Burroughs’ trademark. Like Dale Gribble, William S. Burroughs worked as an exterminator and had an interest in firearms.
Dale also resembles Hunter S. Thompson, with his bald head constantly covered with a hat, always wearing sunglasses, chain smoking, distrust of government, and love of firearms.