iOS 12 introduced Apple’s Memoji feature in Messages. Apple announced Memoji at WWDC in June 2018, and the feature arrived with the public release of iOS 12 on September 17, 2018.
Memoji lets users build a customizable 3D avatar by choosing features such as skin tone, hairstyle, eyes, headwear and facial details. In Messages, the avatar can imitate the user’s expressions in recordings, much like Animoji, while also serving as a personalized character for stickers and effects.
The feature is often confused with Animoji, which debuted with the iPhone X and iOS 11 in 2017. Animoji characters are predesigned animals or symbols; Memoji is the user-created avatar system. iOS 12 also added new Animoji characters and extended Animoji and Memoji use to FaceTime, making the feature part of a broader messaging and video-calling update.