what episode does arizona come on grey's
In three episodes of it.
Arizona Robbins
Originally contracted to appear in three episodes, Capshaw's contract was extended to the remainder of the fifth season, with her becoming a series regular in the sixth season.
wiki:14250117
Arizona Robbins [SEP] Introduction
Arizona Robbins, M.D. is a fictional character on the ABC television series "Grey's Anatomy", portrayed by Jessica Capshaw. She was introduced in the show's fifth season as an attending surgeon and the new chief of pediatric surgery. Originally contracted to appear in three episodes, Capshaw's contract was extended to the remainder of the fifth season, with her becoming a series regular in the sixth season. Robbins has been characterized as "quirky", "perky" and is well known for wearing wheely sneakers and a Holly Hobbie pink scrub cap, intended to appeal to her young patients. She was established as a love-interest for orthopedic resident Callie Torres (Sara Ramirez) after the Torres' storyline with Erica Hahn (Brooke Smith) was cut short due to what series creator Shonda Rhimes called "a lack of chemistry".