WhatsApp is reportedly working on animated stickers in its latest betas. This enables a user to superimposea a moving piece of art (e.g. a drawing or character) on a message. A blog has also apparently found that the app is going to replace its existing emoji design with a new one.
https://www.notebookcheck.net/WhatsApp-to-update-its-current-set-of-emoji-stickers-is-working-on-animated-ones-too.418650.0.html