Reference article
Racing Ducks
The player’s team can contain up to six individually named ducks, each with its own racing skills, energy and appearance.
Recruiting ducks
Buy 
Eggs in a world shop, hatch and name each new duck. When the team already contains six ducks, buying another egg prompts replacement of an existing duck.
Choosing racers
Training improves the selected duck only. Assign ducks to 
Tournaments and choose a duck for each ordinary race. The same duck can fill more than one tournament slot.
Names and cosmetics
You choose the names of your ducks. Putting on a hat replaces the duck’s hairstyle, and getting a haircut removes its hat.