Martin and Olivia Olson are an actual father and daughter who play an evil father and daughter on Cartoon Network's Adventure Time. Olivia is an actress, singer-songwriter, and recording artist who plays Marceline the Vampire Queen. As a songwriter, she wrote and sang songs for Disney's Phineas and Ferb. Olivia also sang "All I Want for Christmas Is You" in the classic film Love Actually. She wrote most of Marcy's Super Secret Scrapbook!!! Martin is a comedy writer, songwriter, and poet who plays Hunson Abadeer, Lord of Evil, on Adventure Time. As a television writer, he has received four Emmy nominations. Martin is known for writing Phineas and Ferb, the New York Times bestselling Adventure Time Encyclopaedia (Abrams, 2013), and his satirical book Encyclopaedia of Hell (Feral House, 2011). They live in Los Angeles.