Cathy Smith is a female alien from outer space, specifically the far-off planet Rhapsodia. She comes to Earth with her grandfather, in order to restart the age-old society: the Monster Buster Club.
When Cathy comes to earth, she takes on a human form. In this form, Cathy has right-sided curved blonde hair, blue eyes and a slightly tanned skin complexion. She typically wears a long-sleeved pink top under a green sweater that reaches just down to her abdomen, with her sleeves rolled up to her forearms. Cathy also wears pink pants with matching pink socks and pink converse. Cathy also accessorizes her hair with beads that keep her hair in its normal style. these beads are pink and green, as seems to be the theme throughout Cathy's outfit.
When powered up, Cathy wears the Pink Monster Buster suit, complete with the traditional neon highlights along the seams that glow both in the dark and during special situations. Also with her suit, Cathy wears a pair of pink tinted visors that display a variety of information and are very useful.