(Can be used in other senses, but im just explaining this one)
From Doctor who.
Timelords have the ability to regenerate after severe trauma or
natural wear and tear. Their body
will under go a complete transformation, and although the same person remains, their appearance and personality changes. (In other words, where a
human would die, a Timelord would just change, thereby healing any injury in the process.)However a Timelord only has the ability to do this 13 times. (Doesnt matter much to them, in one life they Usually
live to about a thousand anyway. Notice I said usually.)
The
Doctor: I'd like to see a butterfly fit into a chrysalis case after it spreads its wings.
Polly: Then you did change.
The
Doctor: Life depends on change, and renewal.
Did you see the
doctor after he regenerated?