I hope this will be the last pegboard hooks you'll ever need to try out! Included are some ready-made STLs, but the real point of this post is to distribute the Fusion360 file that you can customize to make any pegboard hook size you want, just by changing a few parameters (Modify > Change Parameters).

To customize:

Open the .f3D file in Fusion 360.
There will be three components: Parts, Round Hook, Angle Hook
Ignore "Parts" (unless you know what you're doing)
Hide whichever you don't want to print, and show whichever one you do
Go to Modify in the menu, and then Change Parameters

The parameters you'll probably want to set are:
HookExtendOut
HookRadius (Round only)
HookAngle (Angle only)
HookExtendDown
ExtraSupportAngle (Angle only)
EdgeFilet

Each parameter has a description to help explain what they're for. Also refer to the included image showing the parameters' locations on the actual hooks.

Export as STL and then use your slicer.

These are designed to be a bit tight. They fit perfectly printed on my printer and in my pegboard, but you may need to experiment. If they're too tight to fit into the holes, you can:

Decrease the parameter ThicknessWidth
Increase the parameter EdgeFilet (will further round the corners)
Decrease the Z-height in your slicer

If they're too loose, do the opposite.

I print them at .2 or even .24. For strength, the number of top and bottom layers is most important factor. Start at around 1mm top and bottom, and 3 walls, and go from there.