Did you know that Ariana Grande has some pretty serious allergies? Or that Jennette McCurdy is terrified of something that most people enjoy?
Some of your favorite Nickelodeon stars, past and present, have some surprising details about themselves that you probably don't know. Details about their past TV appearances (that you totally won't recognize them from), or their crazy fangirl moments.
Watch the video, and click through the gallery below to find out 10 shocking Nickelodeon star facts. Plus, take to the comments to let us know which shocking fact surprised you most!