The axolotls can be caught using an empty bucket, which is not supposed to, This creates a situation where you can place the water without filling the bucket with water.
Step to Reproduce
1. Get an axolotl and get them with an empty bucket.
2. Place the bucket of axolotl on the ground.
---> Infinite water source by just caught an axolotl.
This made my bucket double after I caught a axolotl.