He calls himself the Fat Man of racing and the flaring sports shirt is his badge at trackside and elsewhere. But today, Johnny Campo was giving everybody a message when he led Pleasant Colony out of the paddock to the Kentucky Derby's post parade. Trainer Campo was wearing a white shirt, necktie and three-piece suit.

He was saying that he had a certain appointment with his excellency, Kentucky Gov. John Y. Brown Jr., in the winner's circle, along with his colt and jockey Jorge Velasquez, for the presentation rituals. How smug could a trainer get, 15 minutes before the race went off? The man who brought it about for Campo was the dark bay colt who had also won the Wood Memorial for him. Pleasent Colony made everything come true in the Derby for Campo and friends after having only four horses licked in the 21-horse field as they settled into the backstretch.

Pleasant Colony picked them up one by one around the far turn and into the turn for home and was lengths ahead with a sixteenth to go. Velasquez was hand riding through the final yards despite an ominous challenge from the 34-to-1 shot Woodchopper. The surging whooshing charge of Woodchopper, who came from even farther back than the winner, marked him as the one to be watched in the 1 1/2-mile Belmont in June.

Never was a Derby more of a trainer's victory. Pleasant Colony was given over to Campo by owner Thomas Mellon Evans after a dismal 13-length beating in the Florida Derby. Campo was also bucking history that showed that he, personally, as a trainer, was 0 for 18 in his attempts to win a Triple Crown race. Moreover, his rider, Velasquez, was 0 for 20 in his Triple Crown riding ventures. Nevertheless Campo was saying through all of Derby Week that Pleasant Colony would win this one. He was managing also to say it without bragging, merely with high confidence.

Campo was banking on the same late-running qualities which enabled Pleasant Colony to win the Wood, and Velasquez was the kind of rider who would not hurry his mount.He waited for the favored Proud Appeal and the other front-runners to come back to him, while threading his way through the crowd on the turns. There was no threat from third-choice Cure The Blues who, like Proud Appeal, finally slowed to a relative walk.

After the race, it was related by one Florida track official that Campo, after taking over the training of Pleasant Colony, had wagered $1,000 on him at the juicy odds of 40 to 1 in the Las Vegas Winter Book when the colt's reputation had suffered in the Florida Derby. Later, when his colt dropped to 10 to 1 after winning the Wood, Campo is said to have sent in $2,000 more at those odds in the Winter Book. This would make his colt's Derby victory today worth $60,000 to Campo, in addition to his 10 percent of the $317,000 winner's share of the Derby. He also is said to have had a $2,000 wager on his Wood Memorial winner at a $12.70 mutuel on that venture.

The biggest losers among the crowd of 139,195 at the Derby today appeared to be John Gaines, the prominent Kentucky breeder, and New York bakery executive Robert Entemann who bought a half-interest in Proud Appeal for $5 million for breeding rights. These syndicators sensed a $50,000 stud fee for Proud Appeal, which would rocket to $100,000 per breeding if he won the Derby, and Proud Appeal would manage 40 of these a year.

Of course, if these men had listened to Campo after the Wood Memorial, they would have kept their steed in the barn today. He said that afternoon at Aqueduct that Pleasant Colony was the one to win the Derby and he has predicted that the colt also will capture the Triple Crown.

Before the race, the 5-foot-7, 250-pound Fat Man, a wisecracker off the streets of New York, was asked to predict who the first four finishers would be. "I can't give you second, third or fourth," he said, leaving no doubt who he thought the winner would be. "The only class in the race if you're handicapping is Pleasant Colony."

Woody Stephens, a noted trainer, passed by Campo's barn this morning and said, "You're going to win."

Campo knew Stephens was right. And had his money there, too. So it came as no surprise that the man in the three-piece suit was a very happy Fat Man when he returned to shed row afterward. As he came to his horse's stud, he yelled, "Touchdown." He embraced his wife, Peggy, and said, "We sure had some fun today." He also left no doubt that he expects more fun on Preakness and Belmont days.

"Everybody thinks I'm a clown," Campo said in his typical tough-guy chatter. "I've been telling you saps all along." A big cigar was clenched firmly between his teeth. He said training Pleasant Colony was child's play. "This is easy," he said. "Anybody can train this horse.You just push a button and this horse wins."

And then he imparted some advice for anyone who wants to test Pleasant Colony in the May 16 Preakness at Pimlico or the June 6 Belmont Stakes. "Let 'em run," Campo said.

"We're going to the Preakness and have some fun and we're going to the Belmont and have some more fun. I was telling everybody this horse was going to win, and they thought I was nuts. We had some fun today. I'm a good horse trainer and don't ever forget it."