Carlos is jumpy and anxious, but with the skills of a true tech prodigy. He’s been working feverishly on a project that would connect the Isle of the Lost to the outside world. Although he inherited his mother's love of fashion (especially if it's in black-and-white), he didn't inherit Cruella's love of dogs ― on the contrary, Carlos is deathly afraid of dogs (though it turns out this is because his mother told him dogs were rabid vicious animals that attack little boys who don't behave).
Instilled with an ever-present fear of dogs, Carlos joins the other villain kids as they take on prep school at Auradon to capture Fairy Godmother’s magic wand and set their parents free. His tech-savviness comes in handy when he and the other villain teens get stuck in a bind.
It is suggested that Cruella raised Carlos into thinking that dogs are killers, as well as vicious, rabid pack animals. As a result, this causes Carlos to have an extreme fear of canines, practically allowing them to chase him up a tree.