TMZ Sports has learned ... Under Armour hooked up with the guys from Dez Customz and Kreative Customs to pimp out their footwear as a special treat for the players at the combine.
The guys literally have hundreds of pairs of cleats -- and players come into the room at the hotel, select their shoes, tell the guys what they want ... and the artists go to work.
We're told some of the requests have been for comic book characters like the Hulk and Batman ... some have asked for school colors .