AI, Misskey mascot, a girl with a Japanese student uniform and cat ears pets on the head a tiny mastodon creature, this one is happy. License: CC-By davidrevoy.com. Misskey by Syuilo ( https://github.com/syuilo/ai/commit/15406d0f30c134e641267795e6eb6cc46a66888a ) under a MIT license as far as I can tell... ((It's really hard to find license info for Ai on Misskey... Not cool -_-)) The Mastodon is not looking like the official mascot, just a cartoony Mastodon.
https://framapiaf.s3.framasoft.org/framapiaf/media_attachments/files/109/959/903/171/929/845/original/64d4466fa2d4d9e8.jpg