Morgana is a mysterious cat-like creature encountered by the protagonist during the Kamoshida Palace escape. Plagued by amnesia about his origins, he seeks to restore his memories and discover his true form, convinced he was once human. He becomes the Phantom Thieves' second-in-command, guide, and mascot, adopting the codename "Mona" for missions. His vital expertise navigating the Metaverse and knowledge of Palaces proves crucial to the team.

In reality, Morgana resembles an ordinary bicolor domestic cat with black fur, a white muzzle, piercing blue eyes, retractable claws, and a yellow collar. Only those touched by the Metaverse comprehend his speech; others hear mere meows. Within the Metaverse, he shifts into an anthropomorphic, bipedal mascot form. This guise features predominantly black fur with white limbs, a mask obscuring most of his face except his eyes and ears, a yellow scarf, and a utility belt. He further morphs into a van reminiscent of a Citroën H Van for swift travel through Mementos, adorned with a golden emblem of his head and incorporating his tail and ears into its design. Following Yaldabaoth's defeat and the Metaverse's erasure, Morgana permanently loses this Metaverse form, remaining a cat, though temporary resurgences of his anthropomorphic shape occur during new Mementos incidents.

Morgana initially displays a prideful, arrogant, and sarcastic personality, frequently boasting of his skills and belittling teammates, especially Ryuji. He exhibits a chivalrous, gentlemanly demeanor towards female teammates, harboring a crush on Ann. Beneath this bravado lies profound insecurity about his identity and purpose, coupled with a fear of abandonment. He originally views the Phantom Thieves' activities primarily as a path to regain his humanity, showing apathy towards broader societal goals. His self-doubt intensifies after Futaba demonstrates superior navigational skills, sparking jealousy and prompting a temporary departure to assist Haru independently. This backfires, forcing him to confront his dependence on the team. He reconciles with the Phantom Thieves, acknowledging their bond as his true belonging and shifting his focus towards ensuring their collective success over solely pursuing his own restoration.

Morgana's journey unveils significant revelations about his origins. He regains memories confirming his creation by Igor to serve as Joker's guide against the god of control, Yaldabaoth, resolving his identity crisis. Within the altered reality of Persona 5 Royal, he temporarily assumes a human form: a teenager with dark blue hair, blue eyes, and casual modern clothing, matching the protagonist's height. This form vanishes when that reality is rejected.

In combat, Morgana wields curved swords and a slingshot. His initial Persona, Zorro, specializes in wind magic and support skills like healing. As his Confidant bond with Joker deepens automatically through the story, Zorro evolves into Mercurius, gaining enhanced abilities, and further into Diego in Royal. Key abilities include potent healing spells like Salvation, crafting infiltration tools, enabling Baton Passes after exploiting weaknesses, executing follow-up attacks, aiding negotiations, stealing items, curing allies' status ailments, and shielding Joker from fatal blows. He often serves as the primary healer and support.

During the Phantom Thieves' intricate plot to outmaneuver Goro Akechi and expose Masayoshi Shido, Morgana's involvement is deliberately omitted when explaining the plan to Sae Niijima to avoid complexity, contrasting with the game where his talking nature and role are disclosed. He participates in infiltrating Shido's Palace, a massive cruise ship embodying distorted desires.