Alonso Perez is one of the lead antagonists, along with accomplice Ramon Bada who try to stop Tintin from obtaining a rare Diamond in The Broken Ear. Perez, hailing from San Theodoros, is an engineer by trade and is the leader of the Two. While engaged with Tintin in a mele combat for a Diamond concealed in the Idol, Ramon and Alonso fall into the sea from the S.S. Washinginton but saved by Tintin, Dr. Sarcophagus and Thompson and Thomson. They are then both shown being arrested in Jail after being rescued in New York City.