Vivillon
Vivillon is a new pokemon introduced in gen VI. It has a different form based on where you live.
I'm collecting Vivillons, and I'm only 3 patterns away from having them all! (As of November 2013)
I'm missing the Sandstorm, Jungle, and Monsoon patterns.
It also might have two secret forms, but that's a secret.
Learn more about Vivillon here.