Carl likes to eat, and this caused him to be overweight. When his parents expanded their cable line-up, Carl found himself focusing on a channel devoted to llamas and a show about a superhero called Llama Boy the Super Hero. He has adored llamas ever since, going so far as to join a fan club, the Llama Love Society (which he likely created as he is shown to be the first member). He even turned into a llama once. He is allergic to almost everything, and has asthma. Carl often unknowingly gives Jimmy his brilliant ideas.