1 / 19

Photo By Getty Images

2 / 19

Mary-Kate & Ashley Olsen

Photo By Getty Images

3 / 19

Photo By Getty Images

4 / 19

Orlando Bloom

Photo By Getty Images

5 / 19

Justin Bieber and Will Smith

Photo By Jeff Kravitz/Getty Images

6 / 19

Heidi Klum and Chris Colfer

Photo By Kevork Djansezian/Getty Images

7 / 19

Sandra Bullock & Neil Patrick Harris

Photo By Getty Images

8 / 19

Pitbull

Photo By Getty Images

9 / 19

Nick Cannon & Josh Duhamel

Photo By WireImage

10 / 19

11 / 19

12 / 19

13 / 19

14 / 19

15 / 19

Photo By Getty Images

16 / 19

17 / 19

Photo By Getty Images

18 / 19

Who needs gel when you've got gallons of green slime? We'll tell hair and makeup to keep some handy for the host on show night.

19 / 19

His first time slimed and he already knows proper eye-cleaning technique. Blake is a natural!