The axolotl is a Mexican salamander with remarkable regenerative properties. As Wikipedia says:
The feature of the salamander that attracts most attention is its healing ability: the axolotl does not heal by scarring and is capable of the regeneration of entire lost appendages in a period of months, and, in certain cases, more vital structures. Some have indeed been found restoring the less vital parts of their brains. They can also readily accept transplants from other individuals, including eyes and parts of the brain—restoring these alien organs to full functionality. In some cases, axolotls have been known to repair a damaged limb as well as regenerating an additional one, ending up with an extra appendage that makes them attractive to pet owners as a novelty. In metamorphosed individuals, however, the ability to regenerate is greatly diminished. The axolotl is therefore used as a model for the development of limbs in vertebrates.
Here's a video with more information on the axolotl and its regenerative abilities:
It's debatable whether the researcher's "five-star hotel" claims are legitimate, but it's an interesting video nonetheless. And if you'd rather spend your Friday looking at baby animals, check out this video of a baby albino axolotl or this video of a colorful adult.