Apple is also leaning harder into Memoji this year. Either during setup or when you use Messages, you should be prompted to set a contact photo and name for yourself, which can be automatically sent to iMessage contacts.
If you haven’t created a Memoji yet, this process will prompt you to do so (on compatible devices). You can then also use the new Memoji Stickers Messages app, which automatically creates emoji-like expressions of you.
I’ll admit, it’s pretty cool to be able to send a ‘head asplode’ Emoji reaction, except it’s myhead asploding.
I’ve found that I can use these stickers in other apps like Slack and Discord. But they seem to be treated as decently sized photos, not actual emoji, so they’re pretty large.