An axolotl is a salamander that remains in its larval form throughout its life, while most salamanders go through a metamorphosis during sexual maturity, so it’s not surprising it retains embryonic growth capabilities.

There’s actually a theory that hominid ancestors at some point split off from other great apes by also not going through the typical great ape sexual maturity. For examples humans look a lot more like juvenile chimps that we do sexually mature chimps.