When Ellen DeGeneres tells you what to say, hijinks can ensue! Over the years, celebs and others have played her delightful hidden camera prank on people, in which they wear a secret earpiece and recite bizarre things she tells them to say. Here are seven of the best celebrity pranks, ranked: 1. Emma Watson: The star of the Harry Pottermovies and the upcoming Beauty and the Beast reboot was a sport while talking part in one prank recently. Take a page from The Bachelor's Corinne Olympios , she was made to interview potential nannies...for herself! Watson noted how Olympios inspired her, even using the word "vagine," and was also made to act like a ridiculous, childish narcissist. "I like to potty alone. I don't need you help me potty. But I want us to be like family. And the family that laughs together, stays together," Watson said, pretending to laugh like a maniac. 2. Adele: In 2016, DeGeneres had a woman pretend to be the singer's assistant.