Why not have a fancy dress party and invite guests to wear Letter K Costumes. Explore this section to find your ultimate outfit starting with the letter K. Costumes starting with the letter K include kings, kangaroos and Kiss. Why not defend the realm as a brave knight in one of our many valiant outfits from traditional knights to full suits of armour. If you want to unleash the animal within then beat your chest as the iconic King Kong. If you are looking for costumes beginning with the letter K then this collaboration of costumes is for you.