Little Man in a Giant's World

At 5 feet, 4 inches tall and 165 pounds, Rey Mysterio has spent his entire career trying to prove that bigger isn't necessarily better in the world of professional wrestling. And the best way to prove that point would be winning the world heavyweight championship at this year's Wrestlemania.

If he wins April 2, Mysterio will become the lightest world heavyweight titlist in pro wrestling history. In an industry that has traditionally favored muscular powerhouses like Bruno Sammartino, Andre the Giant, Hulk Hogan and The Rock, Mysterio has proven wrong naysayers who told him he was too small, couldn't have a believable, entertaining match with the big boys, and that he would never even make it to World Wrestling Entertainment.

Now he is fighting for the world title in a triple-threat match against World Champion (and 1996 Olympic gold medalist) Kurt Angle and fellow contender Randy Orton at Wrestlemania 22. Even Mysterio never believed that he would one day be part of the main event at pro wrestling's biggest annual show.

"No, never," Mysterio told ABCNEWS.com. "All my life -- all I ever wanted to do -- was just wrestle. I'm not one of these people who say, 'I should be here at this point in my career,' or 'I should be at this place right now.' I've had people say to me, 'Rey, you deserve much better than this. You should be here.' But I'm not like that. This is what I love to do."

From Laughter to Autographs

Mysterio resembles a superhero more than anyone in WWE. He wears a mask, carrying on a long tradition of colorful masked grapplers who have dazzled audience with a lucha libre -- or "free struggle" -- style of wrestling, made popular in Mexico, that favors acrobatics and high-flying maneuvers.

The real-life Oscar Gutierrez, 31, began training around age 8 and wrestled his first match at age 14. He is a nephew of Mexican wrestler Rey Misterio Sr. and grew up watching his uncle wrestle and train other luchadores. He was mesmerized by them and American wrestling stars such as Randy "Macho Man" Savage and Ricky Steamboat.

Mysterio said he had plenty of doubters when he was trying to launch his pro wrestling career. He was so small that some promoters initially encouraged him to wrestle as a larger-than-average midget -- an offer he declined. All of this prepared him for the obstacles that lay ahead.

"The way my body's chemistry works, no matter how much I ate, no matter how many protein shakes I drank, I couldn't gain any weight," Mysterio said. "In high school, I had a pretty full schedule. After classes I had a job where I would work and then I would go to my uncle's gym and train three hours a day, every day. My classmates would ask me, 'Why don't you go out for football or baseball?' When I told them all I wanted to do was wrestle, they would laugh."

A Tribute to a Fallen Friend

Mysterio did not always have his ring name. He was known briefly as The Green Lizard and then as Colibri (Spanish for "hummingbird") before his uncle honored him by passing on Rey Misterio ("The Mystery King").

Mysterio wrestled for Mexico's World Wrestling Association and AAA promotion and all over the world before attracting the attention of American audiences -- and wrestling promoters -- in the 1994 wrestling pay-per-view "When Worlds Collide." Mysterio then wrestled briefly for the now-defunct, Philadelphia-based Extreme Championship Wrestling before signing with World Championship Wrestling in 1996. He remained there until the organization folded in 2001 and signed with WWE in 2002.

In his 17-year career, Mysterio has won nine cruiserweight titles while competing primarily against light heavyweights (wrestlers who weigh 220 pounds or less) and eight tag team titles. He won some of those titles with -- and from -- his late friend Eddie Guerrero.

The outcome of wrestling matches is predetermined but there was nothing scripted about the friendship between Guerrero and Mysterio. Guerrero, a former WWE champion and one of wrestling's most popular stars, died suddenly at age 38 last November of heart failure. He had a very public battle with drug and alcohol addiction and tried to be an example for recovering addicts in the last years of his life. The coroner's report determined that years of steroid abuse may have contributed to the heart failure.

Guerrero's death devastated his colleagues and his fans. WWE will honor him the night before Wrestlemania 22 when it inducts him into its Hall of Fame. Mysterio, and WWE wrestlers Chavo Guerrero Jr., Eddie's nephew, and friend Chris Benoit will help induct him into the hall.

"It'll be an emotional night," Mysterio said. "I just hope I find the right words -- have the right words -- to induct Eddie the proper way."

Some fans may be uncomfortable with the repeated references to the Guerrero-Mysterio friendship in storylines that have led up to Wrestlemania. But Mysterio insisted references to Guerrero came with his family's blessing.

"We would not have done anything without ... Vickie's [Eddie's widow] blessing," he said. "If anything, Eddie would have wanted it this way. He may have gotten a kick out of some of the things we said about him."

Breaking the Cruiserweight Barrier Big Time

Mysterio said he is looking forward to "stealing the show" at Wrestlemania. Wrestling observers believe he could become champion but also suspect his title reign may be short-lived.

"I think he has a good chance," said Adam "The Phantom" Nudelman, host of "Get in the Ring," an Internet radio program and co-author of "Mysteries of Wrestling: Solved." "They may just give it to get that feel-good moment that happens at some point at every Wrestlemania -- and a Rey victory would provide that.

"But I wouldn't give him until the next pay-per-view [in the following month], for holding the title," Nudelman added. "It would be a great story; it would be fresh. He could be the underdog champion and hold it for a while. I just don't think they [WWE officials] would trust themselves enough to let him hold it for a long time."

But the prospect of a short world title reign doesn't bother Mysterio. He's used to having doubters and is just happy to have his opportunity.

"If the title reign was to come to an end too soon, it wouldn't matter," Mysterio said. "I would still make history. They couldn't take that away from me."

No matter the outcome of his match, Mysterio has advice for anyone who deals with doubters.

"For every person that made fun of me, that made me work that much harder," he said. "Never let yourself down. You always have to push yourself to the edge."

And if he has his way at Wrestlemania, Mysterio will prove that the best things come in the smallest packages.