Markos is a black male tibbit with white-tipped ears and tail and a white patch of chest fur.

A tibbit is a descendant of once-ordinary housecats bred as magicians' familiars, and shift between the form of a housecat, a cat/human hybrid, and a near-human form with minor cat features, including catlike ears and a tail. Wearing a hat, a tibbit in this form can easily pass as human. It is impossible to tell the difference between a tibbit in cat form and an ordinary housecat.

Tibbits who develop their shapeshifting abilities can assume more complex hybrids and even other cat forms, such as medium-sized wild cats and even big cats such as lions and tigers. With practice, related hybrid forms are possible.

Markos spends most of his time in hybrid form, covered in fur. When he wears clothing, he wears a simple shirt and pants, and never wears shoes. Markos stands a little over four feet tall in his housecat/human hybrids and near-human forms, and in housecat form is the size of a typical housecat.

Markos is straight. While friendly to all, he has no sexual interest in the male form.