Supernatural Season 8 Episode 8

Dean: Maybe it's some--some crazy god who watched too much Robot Chicken.
Robot Chicken is a comedy television series created by actor Seth Green which airs on Cartoon Network during the Adult Swim programming block. The series features action figures and other toys in stop-motion animated sketches.

Dean: Look, man, I hate those flying-ass monkeys as much as you do.
Referencing the 1939 movie The Wizard of Oz, based on the novels by L. Frank Baum. Margaret Hamilton plays the Wicked Witch of the West, the main villainess of the movie. The flying monkeys are her personal servants.

Dean: So this animaniac can step through walls?
Referencing the animated WB series (initially on Fox) which consisted of a number of characters referred to collectively as "Animaniacs." The core characters were Yakko, Wakko, and Dot, Warner Brother characters from the 30s who were trapped in the studio water tower for 60 years. Other characters included Pinky & The Brain, Skippy Squirrel, Dr. Otto Scratchansniff, and dozens more.

Dean: You go Invisible Girl and keep an eye on him.
Referencing Sue Storm, the comic book character first introduced in Fantastic Four #1 (Nov. 1961), created by Stan Lee and Jack Kirby. After being exposed to cosmic radiation along with her fiance Reed, friend Ben Grimm, and brother Johnny, Sue gains the power to (initially) turn invisible. She eventually gains the power to generate invisible force fields with her mind as well, making her a far more useful member of the Fantastic Four.

Dean: That's all, folks.
Referencing the Looney Tunes and Merrie Melodies cartoons, which invariably ended with Porky Pig popping out of a drum, and saying, "Eh-eh-eh! That's all, folks!"

Aliases: Crosby, Stills, Nash
Referencing the folk rock group Crosby, Stills & Nash, who made the scene in 1986 with such hits as "Marrakesh Express," "Teach Your Children," "Our House," and "Wasted on the Way." The fourth member of the band is Neil Young, who performed sporadically with the group.

Glass: Whatever you say, Scully.
Referencing the TV series that premiered in 1993 and ran for nine seasons, and featured David Duchovny and Gillian Anderson as FBI agents investigating the paranormal. Anderson played Dana Scully the (initially) skeptic of the two who sought rational explanations for the many supernatural and alien cases that they dealt with.