Harry Styles
When the One Direction singer was ordered to wear an ear piece to follow Ellen DeGeneres' orders, hilarity quickly followed. It's safe to say the pizza delivery guy wasn't expecting such a special stop.
Taylor Swift
We can't shake this prank off! Ellen DeGeneres scared the "ME!" singer so much that she fell to the ground! Fortunately, everyone can laugh about it and watch it again and again.
Kris Jenner
A Keeping Up With the Kardashians star at the 99 Cents Only Store? It certainly happened when America's favorite momager joined Ellen DeGeneres in a hilarious prank that has been viewed more than 6 million times.
Milo Ventimiglia
The This Is Us star couldn't believe what he was experiencing when a page named "Constance" entered his dressing room. Ultimately, it was Ellen DeGeneres planning another epic prank on her guest before showtime.
Melissa McCarthy
When Ellen DeGeneres gets into your favorite celebrity's ear, anything can happen! Such was the case when Melissa headed to the cleaners and pretended to feel ill.
Justin Bieber
Think you're coming for a casual conversation? You better think again! Ellen DeGeneres is notorious for scaring her guests midway through their interviews. It certainly happened to the "Baby" singer when a mystery person popped out of what appeared to be a table.
Dennis Quaid
Dennis Quaid is here! As fans know, the actor has always been a great sport at pulling off stunts during his visits on The Ellen DeGeneres Show. One of our favorites was when Ellen got into Dennis' ear as they pranked a tow-truck employee.
Bruno Mars
Ellen, your pranks are amazing...just the way you are! Before appearing on the show, the Grammy winner pretended to be sick as a nurse came to his dressing room. With the help of Ellen DeGeneres, Bruno pulled off quiet the impressive joke.
Idina Menzel
Even when Ellen DeGeneres is away, her co-hosts will play! The team at The Ellen DeGeneres Show were able to freak out the Frozen star with a real-life Olaf.