Regeneration

Regeneration is a super-power. It represents the ability to regenerate lost or damaged tissue through automatic biological processes, or by mechanical means. In some cases, the ability can completely regenerate a living organism in its entirety, even after all normal bodily functions have ceased. This is actually a trait common amongst many reptiles, such as lizards, who are known to regrow missing legs or tails.

In fiction
This ability is most commonly seen in the Doctor Who multimedia franchise. The Gallifreyan Time Lord known as the Doctor can regenerate into a new form upon the demise of his previous form. Although his memories, and some aspects of his personality may carry over into the new form, the body is completely different from the old one. Sometimes the regenerated forms are older than their predecessors, and sometimes they are younger. A Time Lord can also regenerate missing limbs, though they grow back looking the same as the did in the Doctor's current form. A prime example of this is when the Tenth Doctor, in his very first adventure (after having already undergone a complete physical regeneration from the Ninth Doctor), regrew a missing hand that had been lopped off during a sword fight with the alien leader of a race called the Sycorax.

In Marvel Comics continuity, the superhero known as Wolverine possesses accelerated healing as a function of his normal mutant abilities. However, he can also regenerate lost skin, hair, teeth and limbs, all of which would not normally heal under normal processes.

Another Marvel Comics character with this ability is Curt Connors, also known as the Lizard. In his human form, Curt Connors is an amputee, but when he transforms into the Lizard, he regrows his missing arm. Connors loses the extra appendage when he becomes human again.

In DC Comics, regeneration is an ability that is also common to both Green Martians and White Martians. This is an application of a Martian's natural shape-shifting ability. Another green DC Comics character with this power is the Swamp Thing. As he is an elemental, whose physical form is tied to the Earth, the Swamp Thing can regenerate and enhance any part of his body that he so chooses. This is done by absorbing raw material from the environment around him. Certain conditions may prevent him from healing, such as being frozen.

There are many supernatural creatures that can regenerate damaged tissue, including Vampires. This too is considered a higher form of accelerated healing. Generally, the older and more powerful the vampire, the more efficiently he or she can regenerate limbs. Not all vampires possess this ability however.

Appearances

 * Doctor Who: The Parting of the Ways
 * Doctor Who: The Christmas Invasion
 * Doctor Who: Utopia - The Master regenerates from Professor Yana into Harold Saxon.