THIS SCRIPT REQUIRES GHOST.ZH TO BE SETUP. So make sure you have that properly setup first!

Other than that, the setup for this script is pretty easy.

When you have ghost setup, go ahead and create an enemy for the keese. Here are the properties you need for this script to work:

Type: Other (Floating)
E. Anim/F. Rate: Set this to whatever is most applicable to the tiles you have handy. (Make sure you use one of the flying options if you have multiple directions.) For the tiles I included in the second screenshot, set it to 4-Frame and a frame rate of around 8.
Random Rate: This is number of 8-pixel segments the keese will fly before changing directions. 1 is 8 pixels, 2 is 16 pixels, etc.
Homing Factor: This is the percentage chance (0-100) that the keese will go after Link when changing directions
Misc Attr. 11 (Under Data 2): Set this to the value of GH_INVISIBLE_COMBO or -1.
Misc Attr. 12 (Under Data 2): Set this to the script number you assign FireKeese to

If you want the keese to be hurt by the level 0 boomerang, be sure to check "Damaged by Power 0 Weapons" under Misc. Flags!