Hollywood's Biggest Pranksters!

Who doesn't love pulling a hilarious prank on unsuspecting victims every now and then? These celebrities sure do! From Cameron Diaz to Fifth Harmony, these stars are Hollywood's biggest pranksters:

1. Cameron Diaz

We think it's safe to say that Cameron Diaz is the ultimate prankster. No one is safe around this Cubana -- not even babies! The Other Woman star recently pulled a prank on Jimmy Fallon's baby. "You pranked my baby," Fallon said. "My baby was 6-weeks-old." Diaz replied, "She fell asleep first. That's what happens when you fall asleep at a party." So what was the prank Diaz pulled on Fallon's little one? "You put her hand in a cup of warm water," the late night show host declared.

2. Adrienne Bailon

Did you catch Adrienne Bailon on Oxygen's Celebrities Undercover? Bailon pulled the ultimate prank on her fans when she concealed her true identity through the use of prosthetic make-up. "I’m a huge prankster!" Bailon told us while discussing her Celebrities Undercover episode. "I love pulling pranks on all my friends and this show is just going to give me the opportunity to do it on a whole other level, with obviously the hair and makeup staff – they literally transform me and [we] pull off the craziest prank ever."

3. Fifth Harmony

The girls of Fifth Harmony just like to have a good time! For X Factor judge Simon Cowell's 54th birthday, they decided to toilet paper his house and posted a huge sign in his driveway wishing him a "Happy 87th Birthday." On April Fools Day this year, while touring with Demi Lovato, 5H thought it would be fun to prank Lovato with a pie to her face. "The prank with Demi was Dinah’s idea and [she] was the mastermind behind it," 5H member Camila Cabello told us during a recent interview. "Dinah had been planning with one of Demi’s good friends, Marissa. She had Marissa tape the whole thing. It was like, we were all standing around talking to her, and all of the sudden Dinah was like, 'I love you Demi!' And she went to say, 'Aw I love you too,' and Dinah like splattered the whipped cream in her face. It was hilarious!"

4. Demi Lovato

Demi Lovato loves pulling pranks! She pulled the ultimate prank on fellow judge Simon Cowell while she was on The X Factor, but it was her latest stunt that had fans dying of laughter. During Lovato's Neon Lights tour earlier this year, the 21-year-old singer took the stage disguised as a snowman while her opening act, Little Mix, was performing. You can watch the hilarious moment in its entirety here.

5. Selena Gomez

While Selena Gomez was still dating Canadian singer Justin Bieber, he decided to buy himself a grill. Gomez was not loving the fact that Bieber would be walking around with this gold mouthpiece day in and day out, so she decided to pull a prank that would get him to change his mind about the grill. The 21-year-old "Come and Get It" singer made Bieber believe she too was going to get a grill and the Biebs freaked! Needless to say, we don't think he went through with rocking the piece of hip hop jewelry.

6. Victoria Justice

While Victoria Justice was touring with Big Time Rush in 2013, she decided to play a fun prank on the guys. “We played a show in Pittsburg and my sister is on tour with me as well. We decided to prank the boys. We got water guns and hid in their dressing room and as soon as they came offstage after this long show, a friend of theirs gave us the signal and my sister and I ran out from hiding and started squirting them like crazy,” she told MTV. “It was hilarious. They were laughing and then James [Maslow] stole my water gun and started squirting me, so it was really fun. They’re really funny.”

7. Gerard Pique

Prior to the birth of his baby boy, Gerard Pique pulled a prank on Shakira's fans. The soccer star took to Twitter in December 2012 (roughly a month before Milan was born) to share a fake birth announcement. "Our son has been born!” he wrote in Spanish. “We’re very happy! Thank you all for your messages!” Fans of the father-to-be soon figured out it was all a joke when they realized it was Dia de Los Santos Inocentes, a holiday similar to April Fools, in Spain and parts of Latin America.