Axolotl has glitched animation when they stood

So i saw axolotl in any split seconds. it starts making axolotl's animation glitch and its stopped in 1 second. I focused.

Step to reproduce:

1. Build the glass bowl and place the whole water inside of glass bowl
2. Put the axolotl inside of water
3. Just look closely to axolotl when it starts glitching axolotl animation (up and down animation)

(Testing purpose: for axolotl where it glitch the animation)