As a plesiosaur, she has a long neck, though shorter than an Elasmosaurus, and a moderately sized head, resembling a transition from one taxon to the other. Her flippers are much shorter than normal in plesiosaurs, but still powerful. While she does eat mostly Fish, her teeth are those of opportunistic predators, and she too will eat anything else available, but promises to not eat the Happy Feet family and friend's species unless they allow it (mainly those they hate).
She doesn't mind moving around on land very much (older and smaller plesiosaurs were considered to behave like Seals and sea lions, being amphibious), either by waddling or belly-sliding.
Midia is caring (mainly to those who deserve it), humorous and occasionally aggressive. She becomes best friends with Gloria, and enjoys her singing along with Mumble's dancing (doing some of it herself in both of these), she also thinks Lovelace, Ramón and Sven to be funny and The Elders (Emperor Penguins), Bryan the Beach Master and Mumble and Gloria's parents,except Norma Jean, kind of jerkish and cruel, but still has a heart for them.
She even got herself a heartsong, called "Trap of Love" by the Hex Girls.
- The song "Trap of Love" comes from Scooby Doo: Mystery Incorporated.