<P> Star Butterfly is a magical princess from the dimension of Mewni . On her 14th birthday, she receives the family heirloom wand . After she accidentally sets fire to her castle, her parents decide that a safer option is to send her to Earth as a foreign exchange student . She befriends Marco Diaz and lives with his family while attending Echo Creek Academy . Star and Marco must deal with everyday school life while protecting Star's wand from falling into the hands of Ludo, a villain from Mewni who commands an army of monsters . Star and the folks from Mewni are able to travel across dimensions using "dimensional scissors" that can open portals . </P> <Ul> <Li> Star Butterfly (voiced by Eden Sher)--The titular character is a magical princess from the dimension Mewni . On her 14th birthday, she is given the family heirloom, but after she causes a big accident, she is sent to the Earth dimension as a foreign exchange student . She then lives with the Diaz family . She enjoys exploring and being away from her parents and their pressure to make her into a perfect princess . Nefcy had originally designed Star as a fourth - grader obsessed with Sailor Moon and wanting to become a magical girl despite not having any powers . The design was initially just her with heart cheeks and the devil horns came later . By the time she pitched the idea to Disney she had made the character older, and an executive suggested she would have actual magical powers, leading to the current foreign exchange student concept . Nefcy says Star is very much like her, and that she has a lot of flaws and aspects of being a real girl . Star is Eden Sher's first voice acting role . Sher describes Star as Disney's first - ever kick - butt princess and identifies with her a lot: "She's always wrong . She's always messing up . But at the same time, this character has such a good heart . Star is fiercely loyal when it comes to her friends and never backs down from a fight . There's so much going on there . And that's what makes this character so much fun to voice ." </Li> <Li> Marco Diaz (voiced by Adam McArthur)--Marco is a 14 - year - old boy who becomes Star's best friend and partner in their inter-dimensional adventures . Prior to meeting Star, he was known as a safe kid . He helps Star during their fights against the villains . Nefcy originally conceived of Marco to be a kid obsessed with Dragon Ball Z and karate . After Star's character was changed to be a foreign exchange student, she felt Marco's character needed to balance out Star's, so he became more of a straight man yet is still quirky . Some of Marco's character was based on Nefcy's husband (filmmaker Bobby Miller). She likes that McArthur portrays him away from being nerdy or unlikeable and that Marco is smart and thoughtful . His middle name is Ubaldo, as shown on his test paper in the episode "Matchmaker". </Li> <Li> Ludo (voiced by Alan Tudyk)--Ludo is Star's nemesis from Mewni . He plans to snatch Star's wand and use its powers to take over the universe . He is a short, dark grayish - green monster with a round head and a beak and wears a cap made out of the upper part of a creature's skull . Ludo commands an army of monsters . In Season 2, he acquires a new wand made partly from the fragments of Star's original wand . His new minions in season 2 are primarily a giant spider and a giant eagle, whom he refers to as girls, as well as a group of rats and some monsters . In the season 2 episode "The Hard Way", he is possessed by Toffee . </Li> </Ul> <Li> Star Butterfly (voiced by Eden Sher)--The titular character is a magical princess from the dimension Mewni . On her 14th birthday, she is given the family heirloom, but after she causes a big accident, she is sent to the Earth dimension as a foreign exchange student . She then lives with the Diaz family . She enjoys exploring and being away from her parents and their pressure to make her into a perfect princess . Nefcy had originally designed Star as a fourth - grader obsessed with Sailor Moon and wanting to become a magical girl despite not having any powers . The design was initially just her with heart cheeks and the devil horns came later . By the time she pitched the idea to Disney she had made the character older, and an executive suggested she would have actual magical powers, leading to the current foreign exchange student concept . Nefcy says Star is very much like her, and that she has a lot of flaws and aspects of being a real girl . Star is Eden Sher's first voice acting role . Sher describes Star as Disney's first - ever kick - butt princess and identifies with her a lot: "She's always wrong . She's always messing up . But at the same time, this character has such a good heart . Star is fiercely loyal when it comes to her friends and never backs down from a fight . There's so much going on there . And that's what makes this character so much fun to voice ." </Li> <Li> Marco Diaz (voiced by Adam McArthur)--Marco is a 14 - year - old boy who becomes Star's best friend and partner in their inter-dimensional adventures . Prior to meeting Star, he was known as a safe kid . He helps Star during their fights against the villains . Nefcy originally conceived of Marco to be a kid obsessed with Dragon Ball Z and karate . After Star's character was changed to be a foreign exchange student, she felt Marco's character needed to balance out Star's, so he became more of a straight man yet is still quirky . Some of Marco's character was based on Nefcy's husband (filmmaker Bobby Miller). She likes that McArthur portrays him away from being nerdy or unlikeable and that Marco is smart and thoughtful . His middle name is Ubaldo, as shown on his test paper in the episode "Matchmaker". </Li>

Star vs the forces of evil who plays star