Axolotls are not hard to care for, but for some reason, my friend (at the time) had difficulty with it. Mango, now Trooper is an Axolotl I got from a friend that he borderline abused. Trooper showed major signs of stress. He was starving to death, surviving in a dirty tank, and living out of a bucket with a filter. Trooper’s bones and ribs poked out of his sides, his tail curled at the end, his gills had became shriveled up, and purple (which is caused by extreme stress and lack of oxygen). He couldn’t even reproduce! He had mentioned months prior that he had an axolotl when I brought up wanting one. Other than that, he never mentioned him.
August 24th, 2019, and he randomly asked if I wanted him. I was so excited for my axolotl to have a friend, but I was very wrong. The poor guy, three years old and half the size he should’ve been. I put him in the tank with my other Axolotl. Trooper instantly started to swim around and stare at all the decorations. He even climbed in the fake plants and PVC pipes. I could see the relief in his face to have something to grip onto (especially when he struggled to move).
Relieving Stress
I knew it was a risk putting them together because of the size difference, but they were so happy together at first. The Axolotls would lay together and follow each other around the tank. Trooper even would start eating consistently (he was never used to having a full stomach, so he threw up regularly.). I had to feed him in small proportions for months and slowly introduce more food like I did when Undyne was little. Trooper even got introduced to salad shrimp. I would defrost it in hot water, he was not a fan.

Eventually, Undyne became food aggressive. She later learned if she started biting him, that I would feed her in an attempt to get her to leave Trooper alone. He was too small and weak to fight back. I came home one day, and all his limbs had been ripped off. I felt so upset and angry, especially with myself.
That day I set up a 10-gallon tank, and Trooper was on his own. He loved it! It was sad for a while because he could hardly move. His arms and legs are still growing slowly, but they’re definitely coming back.