Link Bitmoji to use a mini-you in your Snaps
Snapchat acquired Bitstrips, the maker of the Bitmoji app, last year. Bitmoji is a way to create an avatar of yourself from a menu of cartoon features, then use the finished avatar to express yourself however you wish. Any feeling you could possibly think of, from "WTF" to "A-OOO-GA!", is represented in the Bitmoji menu. It's basically an extremely expressive, full-body emoji.
Bitmoji is fully integrated into Snapchat, so now all you have to do is create an account and assemble your avatar and it'll be available in stickers you can slap on your Snaps, as well as filters you can swipe to add.
Try it out: Go to the settings page, tap "Bitmoji," and follow the instructions to create and link a Bitmoji account. Then they'll be available in stickers after you take a Snap.