There are many 3d printed hooks, this one is mine.

Use at least 3 walls ((4 used), I recommend cubic infill at at 15% or more (all in profile) which will print quicker than gyroid.

It was designed for a specific purpose (see lightweight ladder in pic) so is quite shallow. The base is 110mm tall with hole spacing of 91mm, and the load carrying part is 110mm deep. It can be used with 4-5mm or #8-10 screws.

I did some basic static analysis to balance the strength and material usage, image included. Mine is printed in Sunlu PLA+ and I wouldn't have a problem hanging 10kg on this (with safety) but it will take more.

Uploaded with the profile I used, for bed adhesion if you are printing an extra part, I rotated the second copy and nested it tight up to the first to share a common brim. I will update this to use sections that are multiples of line widths and maybe reduce that side chamfer to improve bed adhesion.