After consulting with the ancient magic (i.e. asking other people for help) I managed to come up with a mod that should remove zombie dogs from the game. It should play nice with most other mods, but I did have to remove a couple of entity spawner groups in order to prevent errors, so who knows.
This mod is only spot tested, so I may have missed a grouping (zombie dogs spawn in a lot of different unrelated groups) so feel free to leave me a comment if I missed something.
DOWNLOAD (3 KB)
Credits: WhackIt1
