Alejandro first appears at an ICE holding facility in "Season Finale". After Jason White dies from being struck by a police car, the Whites family decide to adopt a male child to replace Jason. Much like adopting a pet from a pet store, Jeff Corrigan reads Alejandro's background to learn his parents were deported, and let him out of his cage for the Whites to see. Because he only speaks and understands Spanish, the characters always respond to him saying: "Bien, gracias. Y tú? (Fine thanks, and you?)" when he speaks. The Whites decide to adopt him and take him home to South Park, though he hates his new adoptive family and does not want to be with them.
When the Whites brought Alejandro with them to protest the trial of Randy Marsh, he refuses to protest or put on sunscreen to which Bob White forcefully applies sunscreen on his face causing Alejandro to snap and run away. He is later seen destroying buildings and cars. Due to his sunscreen covered face, the public considers him to be "Mexican Joker". The South Park Police open fire, and Alejandro is shot in the shoulder, but he manages to escape. His current whereabouts are unknown and has not reappeared in the show since.
Alejandro wears a pale dark red shirt under an old gray hoodie, dark blue pants with white stripes on the sides, and white shoes. He has short, black, and slightly unkempt hair.