In the new animated show, The Owl House, I have noticed two secrets that are so hidden, that they didn't even wrote them in the wiki site. 1. In the first episode, I noticed in Luz's flashbacks that there's a girl that resembles Amity Blight (Note: her hair is yellow and red while Amity has green and yellow) 2. In Witches Before Wizards, while Luz was continuing her quest, there is a tree (stop at 6:37) that has a carving of a eye and the numbers "∆1413".
That's all i found, fill free to put the notes in the owl house wiki site, sorry for a unrelated segment, just want fans to not miss any secrets.