One of the most popular ambassadors for the University of Iowa towers ten feet tall, has such a thick neck that two Hawkeye ties are required for special occasions, and is covered with 1,500 henna-hued cows' tails.

Occasionally, he dons a dashing Zorro hat, cape, and mask and thrusts a red rose between his teeth. At Easter, he sports enormous pink satin bunny ears and a white fluffy tail, while on Presidents' Day he adopts the somber air, whiskers, and stovepipe hat of Abraham Lincoln.

Enter the Dress the Sloth Contest.

Rusty, the replica giant Ice Age sloth (Megalonyx jeffersoni), is the star of the UI Museum of Natural History and, by museum coordinator David Brenzel's reckoning, a perfect goodwill ambassador for the university. Every year, some 10,000 schoolchildren from across Iowa trek to the museum. Invariably, Rusty is the highlight of their study trips. Perhaps they're smitten with his benevolent air or the twinkle in his glass eye. Whatever the reason, kids (and adults) love Rusty.

For many families, it's becoming a tradition to visit the museum and see the sloth's latest outlandish costume. Rusty helps keep the UI connected to the lives of Iowans, says Brenzel. Indeed, the sloth is such a well-known icon that he now has pride of place on the new-look banners that hang outside the entrance to Iowa Hall. "With thousands of schoolchildren a year for the past 17 years, that adds up to a lot of kids who will remember the UI," Brenzel adds. "I wonder how many of them come back to see Rusty when they're freshmen."

The spruced-up sloth debuted about five years ago to help break the ice at a convocation celebration being held at the museum. Santa Claus, a hula dancer, and a Thanksgiving pilgrim are now included in his repertoire. Museum staff and volunteers have become dab hands at fashioning pith helmets out of papier-mâché and bunny tails from fleece material and Styrofoam peanuts. "The volunteers love doing this, and I encourage them," says Brenzel. "If they apply to graduate school or go for a job and tell the interviewer that they designed a Zorro costume for a ten-foot sloth, who could possibly turn them down?"

Over the years, only one person has given museum staff a dressing-down for dressing up Rusty. Most people are delighted to turn a corner and discover a giant sloth pretending to be Zorro. "This is serious fun. Rusty is an important figure for leading the charge and getting kids interested in science," says Brenzel. "Iowa Hall's founders were farsighted in the way they anticipated the industry's recent trend towards family-friendliness, and they would respect this effort to reach out to people, especially youngsters.

"When we dressed Rusty as the Easter bunny, the kids loved it, of course. But, more importantly, the parents appreciated that we were doing this for the benefit of their kids."

As for future outfits, Brenzel has a few ideas up his sleeve—perhaps a bridal veil, or a pink tutu. As he points out, "Rusty's the kind of guy to break down stereotypes."