This is another collection of activities to practice possessive pronouns. The one described in the post is really fun. I’ve done things like it before. I’ve even done variations where I just take stuff off of student’s desks, which makes them laugh very hard (and can be a great way to bust a student who is reading a book in class or texting on their cellphone).
The one I ended up adapting is the “Whose Is It?” handout and it’s just been updated to be more workable online, which is nice. But it would make a great in-class exercise as well.