Blue Cap is a student at the South Park Elementary. He has no name on the show, but is sometimes called Brad Dixon by fans after Butters mentions the name in "The Ring". Nevertheless, he has remained a background character since the first season. Although he is a background character, he has an advertisement for the FAQ on South Park Studios.
Blue Cap wears clothes that are very similar to Craig's usual garb - he wears grey trousers, a blue coat and a blue cap with a yellow brim. He appears in almost every episode up until 4th Grade. Since then, his background appearances have slightly decreased. In the episode "Mr. Hankey, the Christmas Poo", a purple version of him is seen during Kyle's number, "The Lonely Jew on Christmas", then he appeared in his usual blue in "Damien". A green version could be seen in "Tonsil Trouble" shortly before Kyle and Cartman fight.
Despite having been the boys' classmate since 3rd grade, the closest time of his voice being heard was a short grunt of pain after being hit by a dodgeball in "Conjoined Fetus Lady". He appears as a background character numerous times throughout the show.