Her ship contains a vast treasure, and she would have her ghost pirate crew tell stories about the treasure in an attempt to lure other pirates to the ship and turn them into members of her crew. Those who are alive can not harm the ghosts, and the ghosts can only harm the living on the ghost ship. One of her ghost pirates told Ioz about the treasure, and when Ioz came to look for the treasure, Cressa told her henchman that he had chosen well as Ioz was "as handsome as he is greedy". Ren and Tula tries to save Ioz, but they were unable to do anything as they could not harm the ghosts.
Cressa seemed to be quite taken with Ioz, and wanted him to replace Grovis, her first mate. While trapped on Cressa's ghost ship, Ioz slowly began to turn into a ghost himself, and by moonrise he would be one forever. Since the only thing that could harm a ghost was another ghost, Ren and Tula realized that the only way to save Ioz was to have Tula use her powers to separate Ren's spirit from his body. Cressa puts up a good fight against Ren, but Ren eventually manages to knock her off the ship, giving him enough time to free Ioz while she climbed back on board.
Cressa is voiced by Kate Mulgrew