Axolotl

Axolotls are mole salamanders that lived only in Lake Xochimilco and Lake Chalco in Mexico City. Because of the rapid urbanization, however, the axolotl is now on the endangered species list.

The axolotl exhibits neoteny, in which the animal remains in its larval form throughout its adult life. It keeps its gills and fins, and it doesn't develop the protruding eyes and eyelids. But it does grow larger than a normal larval salamander. It also reaches sexual maturity in this larval stage.