Oyster War

The Vegetable War was a war on the planet Teppala which raged from 2662 to 2674 AD. It was so violent that nearly all large animals were killed, leading the people who survived the war to become vegetarians, at least inland.

Parties to the conflict were:

• Litila, actually an alliance between Litila and Thaoa which promised to fight anyone who did not submit to them, even it meant fighting the entire world. Litila is a religion which wants to put a species of worm in control of humans. This is still not the same as the Inkʷa/Ifena/Isyna group, which favors animals in control of humans in general, but not just the one specific species of worm.
• The Gold Empire, actually a part of the Gold Empire that had rebelled and conquered the rest of it.

After the war, the human population of this part of the world was so destitute that they did not fight any major wars for another 400 years, and the balance of power shifted to the colder northern areas of the continent, where large animals had not been affected.