Have you ever seen a creature that seems to smile at you from behind the glass, with feathery gills waving like carnival ...

But wild axolotls, endemic to a single lake in Mexico, are critically endangered due to degradation of their native wetlands, with only 50 to 1,000 individuals left in the wild.

These glow-in-the-dark axolotls can regrow lost limbs — and scientists say studying them could eventually help humans do the same.

With a silly smile and frilly gills, the axolotl has wriggled its way into the hearts of millions, becoming a popular aquarium pet and pop culture icon in video games, children’s books and toy ...

Like axolotls, humans also naturally have retinoic acid. Monaghan says the findings could help scientists engineer a similar biological process to one day allow humans to regrow limbs, he said.