Walter White poisoned Brock Cantillo in Breaking Bad by using a plant called Lily of the Valley. Although the exact logistics were never shown on screen, the show's creator Vince Gilligan explained at San Diego Comic-Con that Walt, dubbed the "Evil Juice Box Man," had somehow planted the poison in Brock's juice box at school. This ensured only Brock came into contact with the poison. Walt's poisoning of Brock was a calculated move to manipulate Jesse Pinkman into helping him eliminate their mutual enemy, Gus Fring. By making it look like Gus was responsible, Walt kept Jesse on his side. Walt later took precautions like removing the Lily of the Valley plant from his property to cover his tracks. This act marked a pivotal moment where Walt fully embraced being the villain, showing little remorse and choosing power over morality. Brock was seriously ill but survived the poisoning and eventually recovered.
