EXCLUSIVE

The Lollipop King from the "Imaginationland" episodes of "South Park" was never meant to be exposed to terrorists, gang rapists or Cartman's testicles ... this according to a new lawsuit obtained by TMZ.

Matt Stone and Trey Parker are being sued by a guy who claims he created a show called "The Lollipop Forest" years ago ... only to have the "South Park" guys ripoff one of his characters for the 3-episode "Imaginationland" series that aired back in 2007.

The character in question is The Lollipop King -- which, according to the suit, is a rip off of a character called Big Bad Lollipop from Exavier Wardlaw's "The Lollipop Forest."

In his suit, Wardlaw claims "Lollipop Forest" is a wholesome family show -- and it's value was diminished when the Big Bad Lollipop ripoff was exposed to "unwholesome language and sexual innuendo."

FYI -- during the "South Park" episode ... Lollipop King gets choked out by a Storm Trooper ... witnesses the carnage of a suicide bomber ... and gets a front row seat as Kyle performs a sexual act of an oral nature on Cartman's nether region (... it was a crazy episode).

According to the suit, filed in federal court in Philadelphia, Exavier is suing for copyright infringement -- and is demanding "South Park" remove all traces of Lollipop King from the "Imaginationland" trilogy.