"Rob Schneider Is…" are a series of image and video responses to the use of fake movie trailers where the actor Rob Schneider is shown acting as a particular character of object for a comedic effect.

Origin

The term was first used with the movies portrayed with Rob Schneider's movie trailer's. These were used within the advertisement of the movies and were not used in any comedy parody perspective in any way.

Use in South Park

The term was used as a mock within the popular American show South Park with the episode "The Biggest Douche in the Universe" where the mock of the actor was used within fake advertisements but with ridiculous characters or items with were shown as a carrot, a stapler, a retarded guy "derp" and the character Kenny.

Production within South Park

At the time of this episode’s original broadcast, Rob Schneider was about to star in The Hot Chick, and had already starred in The Animal. The running gag is that all of the fictional trailers follow the same basic plot: a very successful or unsuccessful man is somehow transformed, whether it be into an animal, a woman, a stapler, or a carrot. This point is furthered in the episode with a trailer clearly showing a plot exactly the same as these, but with almost every word spoken in complete gibberish.
Asked about being parodied on South Park, Schneider responded in an About.com interview: "I loved it. That was genius. I thought the only thing, they were too nice to me…When you’re spoofed by the best people in the business, that’s an honor." “The Biggest Douche in the Universe,” a term used to describe the supposed psychic John Edward, was used again by Penn Jillette in his and Teller’s show, Penn & Teller: Bullshit!
Penn and Teller are friends of Trey Parker and Matt Stone and have stated that this is their favorite episode. According to the commentary for this episode, Trey Parker described the creation of the episode as being centered on John Edward who the entire crew of South Park Studios agreed was "the biggest douche in the universe." That was until Matt Stone asked the question “Well, what about Rob Schneider?” leading to the fictional trailers.

Popularity

The term was received with positive remarks and was known as one of the "best South Park references ever used within the television show". Tons of parodies were made of the saying to advertise and promote the use of the saying with others either with the use of Rob Schneider or another character.