102.1FM is indeed a real radio station based in Estes Park, Colorado, United States. More information is available by clicking on the following link, .
While at the "Spooky Laboratory," Eric Cartman sticks his hand into hardboiled eggs, which he thinks are human eyeballs, gelatin, which he thinks are human brains, and the inside of a horse's anus, which he thinks is the inside of a human body.
Stan Marsh wears a clown costume, Kyle Broflovski wears a cowboy costume, Eric Cartman does not wear a costume, and Kenny McCormick wears a ED-209 costume for Halloween.