During the D&D Celebration 2020 event, a new option for a familiar was revealed in the form of the image below:
I assumed it was official material because it was produced directly by a Wizards of the Coast event, though it does not appear in the the latest book (Tasha's Cauldron of Everything).
Is there any official word on if the material from D&D Celebration 2020 is legal in Adventurers League games and/or ordinary games, or is it essentially homebrew?