LOL
Most of the time, Axolotls I think growing extra toes or limbs due to lost ones bitten off by tank mates. Moon Cookie, my white adult female has I think... 7 or 8 toes growing on one of her back feet. I can't really tell for sure. every time one gets bit off, two grow back in place. Luckily she has not been bitten again on that foot in a long while, so hasn't sprouted any more toes. It also seems that the bones in her front legs are a little short, so she has somewhat stubby front arms. She never really raises her self off the ground, only slightly sometimes.
Bobo, my adult gold female has only three toes and one tiny black stub growing on one foot. It has been that way since I got her a few months back, so I don't know if she will ever fully grow that toe back.
Hailz - I think the extra arm is cute
. It just makes him really unique. One of the axolotls that was a sibling to my first axolotl, had a backwards arm. It functioned, but backwards, and the axolotl swam just fine, acted just fine, and I think is still doing fine. He was sold rather quickly, and I think it was because probably someone felt bad for him and wanted to help the little guy out