Pecora appears as a young girl with short light blonde hair that rests above her shoulders and green eyes. She has curved ram horns protruding from her head. Although she appears youthful, she maintains a small but noticeable bust, though she admits to Azusa that it is exaggerated to match others and is actually smaller than Azusa’s. As the Demon King, she has no strict dress code, often wearing a black backless and shoulder-less dress trimmed with white fur at the hem, a fur choker, and black fur-trimmed gloves.

Pecora maintains a sophisticated and innocent outward appearance but is mischievous at heart and loves teasing others. She adopts a mature personality when acting as Demon King, but around Azusa and her family, she becomes playful and manipulative. Pecora has a history of frustrating Azusa, such as sending her on a pointless quest by withholding information. While she calls Azusa her sister and claims her feelings are sisterly, she often hints at romantic interest. In Season 2, Episode 8, she refers to an invitation to an art exhibition as a date.

Little is known about Pecora’s past, but she has been the Demon King for most of her life and is also a popular idol.