Axolotl will get stuck on a lilypad, they will try to enter accessible water and if they walk onto a lilypad they will spin trying to get to the water beneath them. This can happen naturally with lilypads that spawn touching the bank of a water body, and if there is water all around the lilypad they can still get stuck.
Environment
Windows 10, 64bit, Java 1.8
Duplicate of MC-208586