You'll be able to add stickers, animated text, filters and more to Memoji and Animoji. Memoji you create in Messages will automatically appear in Clips. You can change Animoji characters in a video even after you've recorded it. Apple has improved the AR functions of Clips too, so emoji, animated stickers and objects such as sunglasses can follow your face as you move around.
Apple debuted Clips for iPhone and iPad a couple of years back in an under-the-radar fashion. The update might give you more reasons to use it, as well as getting more out of your Memoji and Animoji.