Minion Rush has a section in the settings panel for gift codes. Here are the combinations of minions to use in order to unlock the corresponding prize:

• 5 score perks – Maid Minion + Hulu Minion + Baby Minion

• Free referee minion – Baby Minion + Fireman Minion + Hulu Minion

• Kung fu taunt – Fireman Minion + Golf Minion + Normal Minion

• Laughing taunt – The Golf Minion + Baby Minion + Mustache Minion

• 5 banana perks – Hula Minion + Mustache Minion + Firefighter Minion