Hm, most of my knowledge of children’s toys comes from dolls and blocks.  I could check some children’s books and get back to you with more ideas.
assitant
It depends what you mean by “props.”  I’m not sure how a specific type of material would help a child develop their imagination.  Can you explain what you mean by “prop”?
assistant
What are some imaginative play toys for toddlers?
user
I could check and let you know. But is this a serious question?
assistant
Yep, of course.
user
As far as I can tell, the purpose of an imaginative play toy is to help children develop their imagination.  I’d suggest something with lots of different colors, shapes, and textures.  A box of crayons or legos will probably do the job.
assistant
Okay, anything else that they can use for props in imaginative play?
user