From AQWorlds Wiki
- They disappear after completing The Lake Hydra Quest.
- You can still battle them via Time Travel Fairy in Mobius after completing all Chiral/Chaos Valley quests or typing /join runix.
- They are the first chaos beast.
- Or type /join hydra then go to playes
- Also, you can go to your Book of Lore, go to Story, press Chiral Valley, navigate to page 2, then press replay next to Battle the Hydra to re-battle them.