This Sunday, the WWE's ultimate underdog Rey Mysterio will once again attempt to defy the odds when he puts his World Championship on the line against No. 1 Contender, King Booker at The Great American Bash. Since capturing the gold at WrestleMania 21, critics and doubters alike have predicted each day to be Rey's last as Champion. At the Bash, Rey will face odds as great as any he has faced before. This Sunday, Mysterio will take on not just a SmackDown Superstar, but a motivated and hungry King. WWE.com caught up with the competitors to get their feelings on the contest as the Bash continues to close in.

King Booker, who has enjoyed a wealth of success since winning the King of the Ring Tournament in May, has turned his focus toward the richest prize in all of sports-entertainment, the World Championship. King Booker was not shy in describing to WWE.com just how much he was looking forward to Sunday's pay-per-view.

"Excited is not the word. Overjoyed, that is my word," said the SmackDown royalty. "My quest from Camelot stops at the Great American Bash when I become the new World Champion. I can see it now, the Champion of Champions, the greatest King of them all, King Booker!"

Being a former World Champion and veteran of the squared circle, King Booker knows better than to underestimate the resilient Mysterio. The two have an extensive history, dating back to the mid 90's when they shared a ring in WCW. King Booker claims to know what to expect from the World Champion.

"He's a giant killer," said the King. "He's one of those guys that you don't think has a chance, but somehow, he wills himself to victory. He's willed himself to hold on to that Championship for as long as he has. Rey and I go way back. I'm well aware of his capabilities, I'm well aware of his aerial technique and I'm well aware of the mysteriousness of Rey Mysterio. But, right now, I'm on a roll. I'm on a roll that can't be stopped. King Booker's quest is to become the greatest World Champion of all."

And if he does win the Championship on Sunday, King Booker is prepared to have a celebration of grand proportions, one that both his Queen and Court can take joy in.

"It's going to be a celebration of celebrations," says King Booker. "It's going to be a one-of-a-kind celebration. I might have a week of games. I might have a week of contests. I might arrange for a week of gladiators going one-on-one, all to determine who will have the right to kiss the feet of the King. It will be a royal spectacle."

As everybody knows, wherever King Booker goes, Queen Sharmell and the King's Court aren't far behind. With that in mind, the World Champion takes solace in the fact that at The Great American Bash, he can count on Chavo Guerrero to watch his back.

"It never hurts to have Chavo around," says Mysterio. "Chavo and I go back a long way. I know I can count on him 100 percent and he can do the same with me. Sharmell, Finlay and Regal are always willing to do Booker T's dirty work so it's not going to hurt for me to have Chavo around if I need him. He's been there for me in the past, and if anything happens on Sunday, he'll have my back again."

For Mysterio, who continues to live an impossible dream, preparation for a match like the one which awaits him at the Great American Bash is of the utmost importance. The Champion isn't quite ready to let an entire careers worth of hard work go to waste because of one bad day.

"I've worked so hard for this," said Mysterio. "Booker T is no ordinary opponent. He's an opponent with great skills. He plays mind games and he's good at what he does. I know that I need to be mentally prepared for what he plans to do. Deep down in my heart, I believe that I'm ready. I hope that on Sunday, the Championship doesn't slip through my hands."

The impossible dream will resume this Sunday at The Great American Bash for Rey Mysterio. How long that dream will last though is anyone's guess. If King Booker has his way this Sunday, the dream will end and a royal celebration will begin. What will happen when WWE's most unlikely underdog Champion puts it all on the line at The Great American Bash? One way or another, history will happen and you can be apart of it. The Great American Bash comes to you live from Indianapolis this Sunday at 8/7 CT, and it's only on pay-per-view.