Fish Whacker

I designed and made this about a year ago. I made mine from PETG with 6 walls and substantial infill (probably 75% +). I printed it vertically and it seems quite strong and it's held up to a lot of fish-dispatching. You might want to add some weight in the hollow chamber (pennies, sand, fishing weights...) and add some glue or packing to prevent it from rattling around, before securing the plug with a small screw. Using a brim while printing might be a good idea.