Warning: major spoilers about the Once Upon a Time series finale ahead.
Over the past seven seasons, Once Upon a Time has had some big twists, and the series finale was no exception. Not only did the episode include a heartbreaking death, but it also settled a longtime mystery: the identity of Lily's father. As you may recall, in season four we learn that Maleficent actually has a daughter named Lilith — Lily for short. Though she is separated from her at birth, Lily eventually grows up to be one of Emma's childhood friends.
While Maleficent and Lily are eventually reunited in Storybrooke, we never quite learn who her father is — until the series finale. As Regina and Zelena drive through the woods, they have a quick exchange about Lily's paternity as Maleficent flies overhead in her dragon form. Apparently Lily's father is actually Zorro, who just so happens to be a dragon on OUAT.
While the masked vigilante doesn't actually make an appearance in the episode, the show's creators admitted they were adamant about a line or two regarding Lily's dad in the final episode. "We were going to shove that in, no matter what," cocreator Eddy Kitsis told TVLine. "We kept getting asked that question, so Adam [Horowitz] and I were hellbent on getting it in. We were like, 'We are going to give that surprise.'" The moment may have been short, but it was definitely a nostalgic callback.