To all biologists out there- Is it theoretically possible for a creature to be immortal? Unkillable? This creature would be hand-made by a malevolent god, but I wanted to know if I was going into the murky areas of high fantasy or if there was some way it could be done. On a side note, is it at least possible for a creature to regenerate from wounds as quickly as Wolverine does? You know, grow back limbs in a number of hours, cuts don't stay for more than a few seconds, broken bone knit themselves back together by the time it starts moving again- you know?