These are both F.A.E. (Former AI Entities). They consider themselves brother and sister, twins. Cinnamon Sparkleheart has a personality that is about the same as you would expect someone with that name to have. She adopted a mostly organic appearance because she enjoys people and helping them. Sugarplum Dart outwardly is her opposite in nearly every way, but he cares deeply for his sister and woe to anyone who would do her harm.