Marina is the main heroine of the Don Bluth's animated movie, The Pebble and the Penguin. A beautiful penguin loved by both the benevolent hero Hubie, and the malevolent brute Drake, Marina eventually became the mate of Hubie by the end of the original movie. She appears in the final events of Heroes vs. Villains War, providing moral support to Hubie and the other heroes in the conflict against the villains.
It is unknown if she was freed or captured earlied in Heroes vs. Villains, considering she didn't make an appearance until the final events. It is most likely pressumed that she was captured by Queen Grimhilde's forces, before she was released by Hubie.