In this issue of Blood, Lopez et al undertake the heroic task of characterizing the blood-forming system of the axolotl (Ambystoma mexicanum), an aquatic salamander that provides an excellent model for tissue regeneration and scar-free wound healing. Commonly referred to as the “Mexican walking fish,” axolotls are not fish at all, but rather neotenic salamanders that retain many larval traits throughout their lifespan because they do not undergo a typical juvenile to adult metamorphosis. This retention of larval traits is associated with the profound ability of the axolotl to regenerate many of its tissues, including limbs, spinal cord, heart, and even parts of its brain.-