on the DVD of South Park: Bigger, Longer, & Uncut there is an extended version of the What would Brian Boitano do? as a music video by D.V.D.A (on Wikipedia titled "What Would Brian Boitano Do? Pt. II"). in it it features the following lines close to the end
Brain Boitano was born on the planet of Krylock
He came to Earth to save us all from war and death and stuff
Now the kids are shown to look up to him as in the same music video we see a clip from a much older South Park episode where Jesus is fighting Santa and in the movie they mention he defeated an Evil Robot King in the future and having built the pyramids while beating up Kublai Khan.
I am wondering though if the kids (or any other character) have mentioned that Brian Boitano came from another world outside of D.V.D.A's music video?