Animals will no longer just stare at you and allow you to walk among them, they will now turn against all players and defend their lands.

To start the process, use a splash potion of regeneration, swiftness, and strength (any level) on an animal from the supported list.

This will cause that animal to turn against you and spread the word to fellow animals in a 10 blocks radius around it. The word spreads fast from animal to animal until they raise an entire army. If you see green particles above any animal, that means the word has spread in that area and these animals are hostile to any player within a 20 block radius so be careful.

supported animal list:

cow
pig
chicken
sheep
wolf
horse
donkey
mule
skeleton_horse
zombie_horse
rabbit
panda
fox
polar_bear
turtle

to stop the process, run this command and every animal will become neutral again:

/function eco:eco_reset

Note: eco_reset was only tested within the loaded chunk area and may not work for any animal outside of that area

How to install:

extract the downloaded file and paste the "Eco" folder inside .minecraft > saves > your_save > datapacks

if your game is already open, run /reload to register the datapack

Eco [Datapack]