Scatterbug

Scatterbug is a Bug-type Pokémon from the Kalos region. It evolves into Spewpa when fed 25 candies and its final evolution is Vivillon. It has twenty forms with no visual difference other than the indicator of which Vivillon pattern it evolves into.

Availability

 * When each Vivillon sub-medal is unlocked or leveled up, the Trainer has an encounter with a Scatterbug from the respective pattern. Each sub-medal can be increased when the Trainer pins a Postcard from the pattern's region in the Postcard Book. Each sub-medal takes 3 Postcards to be unlocked, 9 Postcards to be updated the first time, and 15 Postcards to be updated afterwards.
 * When each Vivillon sub-medal is unlocked or leveled up, the Trainer has an encounter with a Scatterbug from the respective pattern. Each sub-medal can be increased when the Trainer pins a Postcard from the pattern's region in the Postcard Book. Each sub-medal takes 3 Postcards to be unlocked, 9 Postcards to be updated the first time, and 15 Postcards to be updated afterwards.

Trivia

 * The Vivillon Collector medal is unlocked and leveled up for Trainers unlocking 3, 10, 16, and 18 unique Vivillon sub-medals VivillonCollector Bronze.pngVivillonCollector Silver.pngVivillonCollector Gold.pngVivillonCollector Platinum.png.
 * Although the description says collecting Vivillon, catching different forms of Scatterbug is enough to unlock the medals.