AC/DC'S "THUNDERSTRUCK" blares over the loudspeakers. Fireworks boom and fog the air. Beside me in the press pit, a woman from The Huffington Post gasps "Oh, my God" as the uncommonly handsome bull riders stride into the spotlight.

"Welcome to the toughest sport on dirt!" the announcer bellows. And so begins the second round.

The first bull vaults out of the gate, the rider clenching the rope with one gloved hand, throwing the other defiantly in the air. He flings himself off before going the full eight seconds required to earn a score, and the bull trots out the exit gate with a minimum of coaxing.

Over the course of the three-hour event, Frank, Shorty, and Darrell "pick up" bulls and "pass" them to each other but mostly stand around, knowing they'll be paid roughly $150,000 this year for looking like studs.

Which, of course, they are. Virtually every bull rider will tell you that clowns have it tougher, in part because they spend three hours a night in front of the horns, not just a handful of seconds. What, then, compels a man to do this?

Darrell is a typical example of the breed, not counting the fact that he grew up in Queensland, Australia. Introduced to rodeo by his rancher dad, he rode bulls at first but switched to clowning, drawn to its selflessness and daring. He briefly attended a clown school, as most clowns do, and trained as much as possible—at practice pens, in unsanctioned local bull rides, on a neighbor's ranch.

Along the way, he developed his own trademark shtick. In addition to protecting the cowboys, clowns are expected to "sell the rodeo," i.e., leave the audience wowed. Darrell's thing was riding bulls backwards. For five years, at the close of each rodeo, he'd lie facedown on a bull's back, hook his legs under the horns, and hold on to the flank strap for dear life. According to Shorty, who was a consultant for the second Jackass movie, Johnny Knoxville wanted to try this but chickened out after seeing Darrell do it.

Not surprisingly, many clowns find strength in God or the bottle. But Darrell has always been a fan of temperance in both areas, and from 1998 to 2007 he worked his way up the ranks. He learned how to read a bull's smallest movements—as little as a lean or a look—and developed a maestro's sense of timing. Eventually, after jitterbugging with thousands of rank-ass bulls, he impressed enough riders and stock managers to be able to hang up his baggy jean shorts and earn his spurs on the PBR tour. That's a major achievement. At any given time, only about a dozen guys make their living as professional rodeo clowns, and Darrell, Frank, and Shorty are now at the top of the heap.

Darrell lives alone in Azle, Texas, outside Fort Worth. In his free time, he runs cattle on a small spread, follows the "as seen on TV" P90x extreme-fitness program, and, inevitably, convalesces. Last November, a bull shattered his tibia and fibula above his left ankle. This weekend, just three months later, marks his triumphant return.