This foldable tent is one of the most loved in our home. EVEN MUFFIN GOES CRAZY FOR IT! :D That actually says a lot.
The tent is about 50cm wide/high/deep and attached in one of the entrances is a ball that make some noise which can be removed if you would rather have it like that.
Flip the tent around to have your cat try it from different angles, and put a toy on top of the roof of the tent - your cat will most definitely smack it from the inside!