If that sounds a touch creepy, well, you're not wrong. According to a GIF that Snap supplied (above), you can appear as an anthropomorphized cat, someone riding a shopping cart, a giant animated "thumbs down" emoji and more. You can add your own message and, as you'd expect, Snapchat will also create facial expressions, mouth movements and more.
If your friend is also set up for Cameos, you can include them in the fun as well. All you need to do is open Chat, tap the emoji button, hit the Cameos icon, tap on a tile and take a selfie. Then, you'll get the option to choose whether you'd like to enable two person cameos. You can send that Cameo to someone else via chat using the same controls.
While a touch disturbing, the feature has high comedic potential and could help Snapchat stay ahead of Instagram and other rivals, at least until they figure out how to copy it. Cameos is rolling out on December 18th to iOS and Android with 150 Cameos, giving you plenty of options for, er, self-expression.