I would love to see the addition of more pocket pals! Huge +1 from me. However, I think it's important that players should be able to easily distinguish between a real axolotl and a pocket pal, so this would be something that would need to be kept in mind.
An axolotl pocket pal seems neat, but 89p does have a point of players mistakening it for a real axolotl. The pocket pals have been non minecraft related for the most part, and I think adding a variety of minecraft pocketpals could be interesting. Overall im a +1 on the idea as this doesnt bring much harm.