Supernatural Season 8 Episode 14

Dean: Get between him and Clifford the big dead dog.
Referencing the gigantic (25') tall) red dog, Clifford the Big Red Dog, first published in a series of books in 1963 written by Norman Bridwell. Initially a runt, Clifford grows to giant thanks to the love of his young owner, Emily Elizabeth. The books were made into an animated PBS series starting in 2000.

Dean: Well, let's go visit the Beverly Hillbillies.
Referencing the TV series The Beverly Hillbillies, starring Buddy Ebsen as Jed Clampett, the grizzled patriarch of the hillbilly family. When he finds "oil in them there hills," he moves his family to Beverly Hills and comedy hijinks ensue.

Cindy: Keep it coming, Ken Doll.
Referencing the Mattel doll, Ken (aka Ken Sean Carson), perpetual boyfriend/husband/significant other to Barbie (Barbara Millicent Roberts) since 1961.

Dean: Do not let J.R. and the gang out of your sight.
Referencing the primetime TV soap opera Dallas (1978-1991, CBS), which features the rivalry between two Texas families, the Ewings and the Barneses. J.R. Ewing, played by Larry Hagman, was the oldest son and the one responsible for most of the scheming and backstabbing among both families. The series was continued on TNT in 2012.

Ellie: The whole Clark Kent look.
Referencing the secret identity of Superman, the comic book character created by Jerry Siegel and Joe Shuster in Action Comics #1 (June 30, 1938). Arguably the most recognized comic book character in the world, Baby Kal-El was rocketed from the doomed planet Krypton, landed on Earth, and gains superpowers under the yellow sun. Assuming the identity of mild-mannered Clark Kent, Superman fights a neverending battle for Truth, Justice, and the American way, and has appeared on radio, television, cinema, video games, and novels among other media.

Dean: See, I get Old Yeller out there.
Referencing the novel of the same name by Fred Gipson (1956), subsequently made into a Disney movie in 1957. Old Yeller is a Labrador Retriever/Mastiff adopted by a young boy, Travis. When Old Yeller is bitten by a rabid wolf, Travis is forced to shoot his beloved dog in a tearjerking scene.

Dean: See if I can't gank Huckleberry Hound.
Referencing the animated blue-furred Southern-accented dog created by Hanna-Barbera in 1957 and originally voiced by Daws Butler. He first appeared on TV in The Huckleberry Hound Show as the featured character, but later teamed up with other Hanna-Barbera characters such as Yogi Bear on a variety of programs.

Dean: If Landshark comes knocking, you call me.
Referencing the sketch character from Saturday Night Live, played by Chevy Chase. Described as "the cleverest of all sharks," the Land Shark's modus operandi involves going up to young women's apartments, posing as a plumber, delivery man, door-to-door salesman, dolphin, etc. They would inevitably open the door and be eaten. The Land Shark first appeared in a parody of the original Jaws movie, in SNL's first season.