Stephanie Yin, from Casey Dunn's Invertebrate Zoology (Biol 0410) course at Brown University, tells the story of a parasitic barnacle with a fascinating lifecycle. Visit http://creaturecast.org for more stories about the unexpected world of Biology. The hand-drawn animations were photographed at the Brown University Science Center (brown.edu/academics/science-center/). Audio was recorded at the Granoff Center for the Creative Arts (brown.edu/academics/creative-arts-council/granoff). Music by King Vitamin (http://www.jamendo.com/en/album/96361), Lino del Vecchio (http://www.jamendo.com/en/track/801778), and Val (http://www.jamendo.com/en/album/51805).