wave?

[BrooklynLexee]

How can you tell what wave your blind bag is?

 

[Manley_T_McDragonpuncher]

All the bags had different artwork depending on the wave. Besides that, there's about 24 ponies each wave, and while some are released more than once (like the mane 6) most ponies only get one release. There are complete lists of all the released blind bags so far here (G4 My Little Pony Reference - Blind Bag Index (Friendship is Magic)) and here (G4 Blind Bag Ponies - My Little Wiki) with pictures to help out if you have loose ones around. If they aren't listed here, they are either a bootleg or an unreleased prototype that got put on ebay or some other auction site. Hope this helps.