Axolotl move in place while game is paused

Axolotl reposition themselves when the game pauses, instead of freezing immediately. This happens with Axolotl on land as well as in water. As far as I can tell, they are the only mob to do this.

Steps to Reproduce:
1. Open a singleplayer world which allows pausing
2. Spawn an Axolotl
3. While looking at the axolotl, pause the game with F3+ESC