CHER has an all-new show at Caesars Palace in Las Vegas, debuting Tuesday, May 6, and only ET's MARK STEINES is inside her dressing room for a sneak peek at the BOB MACKIE-designed looks she'll be wearing for her big show!

Cher's show at The Colosseum is full of chart-topping hits spanning from the '60s to today, from "Gypsies, Tramps & Thieves" to "If I Could Turn Back Time." The spectacle features extraordinary choreography, state-of-the-art lighting and special effects and, of course, those signature, breathtaking costumes.

Cher says she wears 17 costumes throughout the show, and, "My fastest change is a minute-forty five, from head to toe."

Now that the ageless legend is in fighting shape for her performances, would she ever consider competing on "Dancing with the Stars"?

"I don't want to do that kind of stuff," she says honestly. "I've worked myself too hard and too long and tried to achieve -- I have a [expletive] Oscar, okay? I have to do 'Dancing with the Stars'?"

It's not as if she has any time for the hit ABC show anyway, since her Vegas show opens Tuesday and runs four nights a week on Tuesdays, Wednesdays, Saturdays and Sundays.