Syrena, portrayed by Àstrid Bergès-Frisbey, is a mermaid who appears in "On Stranger Tides". She does not appear to be as hostile as the other mermaids. Following the battle at Whitecap Bay, she is captured by Blackbeard's crew, who need a mermaid's tear in order to activate the Fountain of Youth. When the glass tank Syrena is being carried in shatters, she changes to a human form, causing missionary Philip Swift to remove his shirt and cover her. Philip then carries her due to her inability to walk and names her in an attempt to make Blackbeard realize she is a person and not a creature. Philip and Syrena develop a strong bond.