Let’s continue with Telegram stickers. Instead of WebP for animated stickers, a format called Lottie, developed at AirBnB (remember, you could still travel to other countries before?), was chosen.
The main difference is that it is a vector animation and therefore tends to be smaller in size. Examples of animations: https://lottiefiles.com
The primary way to create these animations is in the paid Adobe After Effects with the plugin Bodymovin, which makes a JSON file. Any animated sticker in Telegram is a zipped JSON file in Lottie format.
https://core.telegram.org/animated_stickers
JS library to show animations on the site https://github.com/airbnb/lottie-web
Online editor for creating animations: https://www.lottielab.com
Update 2024-09-01: There is a Figma plagin for creating Lottie animations.