For the Bambu Lab Contest I got inspired to use the PLA that came with my P1S by creating a Helloween piece. I made a Mr Potato Head compatible pumpkin, it's not perfect, but I do believe it's a great starting point.

The profile I used has 3 outer walls, and the piece feels very solid, It might do with only 2, maybe even going back to the original design and thin the skin by 1 mm.

As a toy, I feel it's as strong as it needs to be, If it were to be just a figurine, then thin walls would be no problem.

I don't have experience modeling organic shapes, so my guess is anyone can get the STEP file and get the dimensions from the extension peg and have at it for attachments, I might give it a go myself.

EDIT: I created a few jack o' lantern mouths, a nose, and a cyclops eye, the extender peg is a great way to print the accessories flat when they have an uneven surface on the front.

The eyes seem to be the hardest to model since there's only a single hole for both, so it seem like they need to be kind of merged in order to make them viable. Ears should be a bit difficult as well because of the organic shapes and the small size.