The border patrol officers Charlie/Marcus Andrews, voiced by Matt Stone, and his unnamed superior, voiced by Trey Parker, sit in their guard tower trying to keep immigrants from Mexico from illegally entering the United States. They also are there to prevent Mexicans from crossing the border in the opposite direction, from the United States to Mexico.
While playing Texans vs. Mexicans, Butters, in character as Mantiquilla, inadvertently creates a Mexican revolution, causing Mexicans to abandon their jobs and return to Mexico. This creates a shortage of laborer's causing the border patrol to hire volunteers to keep the Mexicans in the U.S.
Charlie is skinny in stature with brown hair. He is the first to notice the Mexican citizens returning to Mexico. He is later called Marcus by his superior officer. His name-tag reveals his last name to be "Andrews"
Officer Andrews' superior is overweight, has dark brown hair, and wears sunglasses. He seems to be the leader of border outpost. He comes up with the idea of hiring volunteers as extra guards to help prevent the Mexicans from returning to their home country.