Rey Mysterio is widely regarded as the best little man of WWE, but despite his size, he has gone on to win pretty much every title there is.

He's a two-time heavyweight champion, one-time WWE champion, three-time cruiserweight champion, two-time intercontinental champion, four-time tag team champion, and two-time United States champion.

He even stunned the entire WWE universe when, in 2006, against all the odds, he won the Royal Rumble match, meaning he'd go on to headline that year's WrestleMania.

In that event, he lasted one hour, two minutes and 15 seconds.

“It’s crazy. The time doesn’t fly. It feels like it’s forever, but strategies are very important when you step in the Rumble. I think being able to showcase some of my high flying moves, but sometimes believe it or not I would stay low in the corner, you know making sure that whoever was throwing down at the time… just let me chill here and hang out, but it worked.”

He had been away from WWE for numerous years, and it was then when he stunned fans after sharing a picture on Instagram of his new physique, with toned abs, a ripped body and bulking arms.

The transformation is so big that the picture led to some of his fans debating whether he has been using steroids, with one writing: “Amazing what getting on the juice can do.”

Throughout his career, Mysterio has suffered various injuries, including surgeries on his back and knees.

Below are two pictures of Mysterio, one from 2003 and one from 2016.

Just look at that transformation!

After his first stint in WWE, Mysterio tried his hand at Lucha Underground, along with a small stint in New Japan Pro Wrestling

However, The Greatest Mask Of All Time is now back in WWE and is currently working closely with his son Dominick.

Mysterio recently had a feud with Samoa Joe for the United States championship, before crossing paths with Brock Lesnar.