Princess Sam

Doudo, the worshiping alien from "It's No Good to be King", who revered Chris as a king, returns to Singletown and asks Sam to make believe she's a princess, in order to protect a real alien princess hunted by some distant alien warrior looking like a huge pig. Sam hesitates, but accepts. From then on, she has to act exactly like an authentic princess does : she must learn to walk, to talk, to position herself, to smile just like a member of the royal family would. Notably, she's not allowed by Doudo to do anything, including help her friends to hunt down aliens. And all the good deeds Sam had to complete in her schedule – do the shopping for an old lady, help clean the park and so on – are transferred to Chris, Cathy and Danny. Meanwhile, the alien keep on looking for the alien princess, and devouring everything he can, because of his tremendous appetite. When Doudo realizes that the pig-warrior is getting closer, he does all he can to stop him. As Sam decides she can't bear the make-believe any longer, and that she will go help her friends to bust the pig-warrior, ignoring Doudo's warnings, this one traps Sam in a ball and goes to fight his enemy. Once Sam finally gets out of the ball, she joins the rest of the team for the hunt. But the pig-warrior finds her and understands she's no princess. He then manages to locate the real princess, captures her and tries to escape, but the MBC can trap him on the skate ramp in the park and vacuvate him. In the end, Sam confesses she'll never "play the princess" again, as she's really not made for that. (this is episode 51 on DisneyXD USA)