Heathcliff tends to act like the big boss in his neighborhood and is usually considered to be the toughest cat in town. He is smarter than most of the members of his neighborhood and has a habit of stealing food and causing trouble. Although he may appear to be a “bad guy,” he cares about his friends, such as his owner Iggy Nutmeg and even a lost kitten. He also tends to romantic, especially towards Sonja, and often becomes jealous when seeing him with another cat.
Heathcliff appears as an orange, slightly overweight orange cat with black stripes and conjoined eyes. He also appears to have a worm-like tail and a black nose.
Heathcliff cares dearly for Sonja, even going out of his way to steer her away from her crushes and into his presence. This is first shown in the pilot episode titled The Great Pussini when Sonja chases Pussini and claims he is the one she loves. As seen in the majority of the Heathcliff episodes, she is usually drawn by Heathcliff’s heroic deeds in the end, making their relationship unbreakable.