Children's book merch?

My finished product for COP3 is a twenty page book. But I need to think about how else I could apply Susan to other things such as merchandise. I wasn't sure whether this would just be for the sake of it though, so I went on the Waterstones website to see if there's any other products in particular that usually sits with the release of a book. I also thought that because my book is a satirical version of the normal layout of a children's book, that I should look at the merchandise a child's book has...

Stickers, colouring and activity books is something that I think I could out alongside my publication, and could possibly mock up? But I don't just want another book to go with my book, so I kept looking to see if there's anything else.

I think it would be hilarious if I could make a soft Susan plush to go with the book in the same layout to something like this:

If I were to actually put my book in the market this is exactly how I would want it to be packaged. There's a lot of satirical books based on the style of children's books, but I am yet to see a plush that is part of the purchase of the book. I have no idea how to go about the creation of the plush, but that's something to think about in my future for illustration. Or it could be a mini blow up version made with plastic, or could be like a barbie doll? But actually I think a plush would work best because that's what they usually are, a cuddly cute toy to match with their equally cutsie book about a rabbit whose lost its balloon... I wish this toy was something I would have realistically been able to physically make.