Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:6286761.

Turn your pumpkin into Frankenstein!

I printed using silver PETG but could be printing using any material you want.

Once printed make a 5-10mm hole in the pumpkin where you want the bolt to be located and just screw in. You might need to remove some more pumpkin to get the bolt to sit flush.