What do you call a male mermaid? A merman? What if it's Baltimore's own Olympic champ Michael Phelps -- Poseidon, perhaps?

Decide for yourself -- take a look at the swimmer alongside actress Julianne Moore in a portrait from Walt Disney's latest "Year of A Million Dreams" promotion. In a scene shot by Annie Leibovitz, the duo are frolicking in the deep with other mer-people a la Ariel from Disney's hit The Little Mermaid.

"It was kind of weird to be able to put on a tail and swim around in a tank," said Phelps, who was photographed by Leibovitz in L.A. last summer. He joins a long list of stars, including Beyonce, Jennifer Lopez and Julie Andrews, who have all been photographed by the famous photographer as various Disney characters.

You can catch (get it?) the photo in Vanity Fair's June issue.

(Photo: Annie Leibovitz for the Walt Disney Company)