"The Entity" is the tenth episode of the fifth season of the animated television series South Park, and 76th episode of the series overall. "The Entity" originally aired in the United States on November 21, 2001 on Comedy Central. This episode introduces Kyle's cousin Kyle. Creators Trey Parker and Matt Stone have stated the story was inspired by the Segway PT and the general chaotic nature of airports at the time of the production, shortly following 9/11 and the 2001 airline bailout.

A Segway is a two-wheeled, self-balancing personal transporter device invented by Dean Kamen. It is a registered trademark of Segway Inc. It was brought to market in 2001 as the Segway HT, and then subsequently as the Segway PT. HT is an initialism for "human transporter" and PT for "personal transporter."