From PinataIsland.info, the Viva Piñata wiki
- For answers to commonly asked Wild-card questions, see below.
A wild-card is a very rare pinata that is created while performing a regular romancing process. This is not an evolution of a species. Wild-cards are purely random, and any egg has a chance of being a wild card. The only thing that can help your chances of a wild-card being born is if one or two of the parents themselves are also wild-cards.
When a wild-card is born, Leafos will say, "That's Amazing! There's a one in a million chance that a wild - card piñata is born! It must be your lucky day!"
Your rare pinata will have some physical trait that will differ from the rest, e.g., a Moozipan with horns.
Every species has a wild-card version with a larger base value which is increased by 10 times.
Wild-card Hall of Fame
Does hatching an egg with a Cluckles increase (or decrease) the chance of getting a WC?
No. The only thing that will increase your chances of getting a wild-card, is if one (or both) of the parents are wild-cards. View thread