<Tr> <Th> 3a </Th> <Td> 3a </Td> <Td> "Monster Arm" </Td> <Td> Aaron Hammersley </Td> <Td> Aaron Hammersley & Bert Youn </Td> <Td> Dave Wasson </Td> <Td> April 6, 2015 (2015 - 04 - 06) </Td> <Td> 103 </Td> <Td> 0.83 </Td> </Tr> <Tr> <Td_colspan="9"> Marco breaks his arm before a karate tournament . Star uses her wand to fix it, but transforms it into a tentacle arm . As Star tries to find a spell to reverse it, Marco begins to like his new powers associated with the arm . However, the arm harbors an evil sentience that intends to take over the world . </Td> </Tr> <Tr> <Th> 3b </Th> <Td> 3b </Td> <Td> "The Other Exchange Student" </Td> <Td> Mike Mullen </Td> <Td> Carrie Liao </Td> <Td> Danielle Koenig </Td> <Td> April 6, 2015 (2015 - 04 - 06) </Td> <Td> 103 </Td> <Td> 0.83 </Td> </Tr> <Tr> <Td_colspan="9"> When the Diaz family receives a visit by their former foreign exchange student Gustav from Scandinavia, Gustav soon becomes the family favorite with his meatballs, that Star feels neglected . She senses something is wrong when she discovers Gustav harbors some books and media about how to act like a Scandinavian in his backpack . </Td> </Tr>

When does star vs the forces of evil season 3