The players walked from the team's hotel in downtown Denver to "The Delectable Egg," a popular breakfast spot nearby.
"Breakfast of champions," veteran reliever J.J. Putz said.
The presence of the players in costume drew quite a bit of attention among the fellow diners with kids asking to have their pictures taken with them.
"We had kids asking, 'Where's Iron Man?'" rookie catcher Tuffy Gosewisch said. "They were coming giving hugs. People were asking what's going on. It was just a good time."
The team originally was going to have the rookies dress up following last Thursday's game for the flight to Denver, but the Dodgers beat the D-backs that day to clinch the National League West.
"With everything that happened it wasn't appropriate timing," Putz said. "So we pretty much decided not to do it. The guys were all begging after the game yesterday, 'Hey can we just dress up tomorrow and walk to the field?' So we said yeah if you guys want to do it, we'll do it. We were going to bag it for this year."
D-backs manager Kirk Gibson came up with the line of the morning.
"Hopefully, they act like superheroes on the field," he said.
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.