Telegram Bot HandbookManaging Sticker Sets and Custom Emoji Sets
Bots (and only bots) can create sticker sets and custom emoji sets. Each pack must have a user specified as its owner.
A common way for people to create and manage sticker sets is through @Stickers bot, but other bots can do it as well.
Bots are able to create, rename, edit, and delete sets.
Custom emoji
Only premium users may use custom emoji from sets. Nevertheless, custom emoji sets can be created by any bots and owned by any users.
Formats
Sticker sets and custom emoji set may be static (PNG or WEBP), video (WEBM), or animated (in a special format based on Lottie). Furthermore, a set of single color emoji may be adaptive, meaning that users will see it in the same color as the text regardless of their color theme.