The costume appears to be that of a kangaroo, and consists of one piece with boxing gloves attached to the arms and clown-like paw slippers attacted to the legs.
After changing into the costume you discover you have a pouch, which means you'll be able to carry your wallet and other stuff.
As you leave the changing rooms you start tripping over your big feet. You try walking like a skier for a while and then your confidence grows enough for you to start hopping. The costume must have some kind of special elastic because you're hopping just like a real roo!