Peter Pan's shadow is the living shadow of Peter Pan.
In the film, while Peter was visiting the Darling household to listen to stories, their dog, Nana, barked at the intruders and while Peter escaped, his shadow was captured. That night, Wendy Darling discovered it and stored it in her drawer to prevent it from getting into trouble. The next night, Peter and Tinker Bell returned to retrieve it. When they found it, they accidentally woke Wendy. As Peter attempted to stick it back on with soap, Wendy preferred the proper way, and sewed it back on.
The shadow appears in the special episode "Peter Pan Returns". In the special, it escapes and heads for Neverland. While there, it is captured by Captain Hook, who uses the shadow as leverage to capture and exile Peter Pan and have his revenge. Ultimately, the plan fails, Peter is re-united with his shadow, and Hook is defeated.
The shadow makes another appearance in Jake's Awesome Surprise. When Jake opens a treasure chest, Peter's shadow flies out of the chest, revealing Peter Pan himself, who attends Jake's birthday party.
In Pirate Fools Day!, Peter's shadow sneaks away and begins to pull pranks on everyone in Never Land. During his antics, he is captured by the demonic Shade the Shadow Pirate. However, before Pan's shadow is imprisoned in the Shadow World forever, Peter and Captain Jake fool Shade, helping the shadow escape, and the Shadow Pirate is destroyed.
In this show, the Shadow is a demonic entity that resides within Neverland and monitors those who exist within it. When a man named Malcolm chooses to stay there, he gives up his son to the Shadow to retain his youth, and becomes Peter in doing so. The Shadow then becomes his servant, but warns him that his immortality is limited, and will die when his time runs out. Motivated to have companions, he orders it to begin bringing children to Neverland. In London years later, Wendy meets it outside the nursery window, and it takes her to Neverland. However, after returning from a visit, she reveals that it now wants one of her brothers, John and Michael to take back with it. To make sure it doesn't succeed, Wendy, John, Michael, and their friend, Baelfire, hide the next night when it comes back. However, Michael gets distracted by it, forcing Baelfire to dash out and have it take him instead of the Darling children. Kf accepts the offer, and takes him toward Neverland. During the flight, however, he lights a match to ward it off, causing it to drop him into the sea, and after searching for a brief moment, it can't find him and flies back to Neverland. The Shadow appears in present day aiding the Lost Boys in acquiring Henry Mills from the rogue Greg and Tamara. It assists in the attack by stealing Greg's shadow, leaving him in a comatose state, and flies off with its captive. It also appears to Rumplestiltskin as Belle to gain his trust until it is exposed by Regina.
In the Dark Hollow, the Shadow ambushes Emma, Captain Hook, and Neal with two other duplicates of itself. Emma is able to capture it, however, in a candle, and it is then used to allow the Jolly Roger flight to sail them home. After the ship enters Storybrooke, the Shadow remains trapped in the sail, as Peter is incapable of controlling it since he is imprisoned. Unbeknownst to everyone else, he previously switched bodies with Henry. While he is inhabiting Henry's body, he releases the Shadow from the sail, where it then steals that of Mother Superior the following morning.
During the night, the Shadow overhears a plan the residents of Storybrooke have to switch back Henry and Peter to their respective bodies. Upon learning David, Hook, Neal, and Tinker Bell are going to procure the Black Fairy's wand for the task, it follows them to a church and attacks. It knocks Captain Hook off his feet, but is captured when Tinker Bell lights a flame on a coconut to draw it in, and proceeds to throw it into an open fire, killing it and returning Mother Superior's to her body.
The Shadow is first shown when Peter send your avatar on a mission to find it. It is like a meet-and-greet character except you must copy his movements and find it three times throughout Disneyland.
The Shadow can be seen during the game's opening when the player is operating as Tinker Bell. It appears in a bedroom (presumably the nursery) when Tinker Bell flies through, briefly surprising it.
The Shadow can be seen flying through the walls in the popular dark ride attraction Peter Pan's Flight.
The Shadow plays a significant role in Disney Dreams! Here, the shadow unleashes some of the magic from the Second Star to the Right. As it enjoys itself with some of the Disney characters, he is attacked by Captain Hook and his Disney villain allies. Peter and Tinker Bell arrive and successfully restore the magic, defeating him.