A puppy’s jaw spontaneously regrew after Cornell veterinarians removed a majority of his lower left mandible due to cancer. Although this phenomenon has been documented in children, this is the first reported case of its kind for dogs of any age or breed. Tyson, a three-month-old French bulldog, was...
On the on hand he was only three months old, and still growing. On the other hand it only took two months for his jaw the grow completely back. That's pretty crazy.
I remember listening to a podcast about this subject and was quite surprised to find out that the ability to re-grow limbs is way more common than we've previously thought and I think they were saying that the same mechanism that allows this to happen on other species is present on humans aswell.