I was just about to say that they look to be 3D-printed, and that you should look up the material used, when I saw it at the bottom of the page.
However, Ive worked a bit with 3D-printers, and I would suggest that you contact them and ask how they remove the support material from the printed piece, because some printer's pieces need to rest in a highly toxic chemical bath to dissolve the supporting plastic structure to get the finished piece.
Essentially you add other stuff than the finished product to help stabilise during the print. Not all printers work the same though, many technologies out there, but I would ask anyway.
Okay, tech stuff aside, I think it looks to be a very fun and great toy to be honest, maybe not to be used everyday but now and then!

I am also quite sure that Leroy would just throw it out of the bowl

!