The six immortal animals

Surprisingly, there
are some animal species that, for
whatever reason, have simply decided
that they don't like the idea of death and
that they will have no part in it. These
animals are functionally immortal. They
never age, and-- unless an outside force
does them in-- they could theoretically
live forever.
The Sea Anemone
The lowly sea anemone doesn't look like
an immortal animal. In fact, it doesn't
even look like an animal. In between
swaying to the left, swaying to the right,
and occasionally swallowing a bit of
debris, this brainless polyp is busy
defying everything we know about
mortality. A sea anemone doesn't age as
it gets older; it simply grows bigger.
Fortunately for those who find this a
little creepy, none of them have lived
long enough to develop sentience yet--
they get wiped out at around age 80 by
heat, water pollution, infections and
greedy collectors.

The Lobster

Like the sea anemone, the lobster is an

idiot. It has no brain, and its central

nevous system is about as simple as a

common household insect. But lobsters

have somehow figured out a way to defy

aging as we know it. Unlike people,

lobsters don't experience any change in

metabolism or body-function as they get

older. A one-hundred-year-old lobster

will even continue eating, moving and

making baby-lobsters without any sense

of shame. They also keep getting bigger--

meaning that, after a couple-hundred

years, they can be the size of a wolf, and

capable of scaring the living daylights out

of anyone 

The Aldabra Giant Tortoise

Aldabra giant tortoises are exactly what

they sound like-- freaking giant. The

males can weigh nearly 800 pounds,

which would make them the most

terrifying animals in the world if they ate

meat and moved a little quicker.

Fortunately, Aldabra tortoises barely

seem to notice humans like us-- they

aren't tame; they simply don't care.

Because, inside their little reptilian

brains, they are laughing at the fact that

we get old and die. We aren't sure just

how long Aldabra tortoises live, because

they have a pesky tendency to live longer

than the people watching them. The

oldest confirmed age of an Aldabra

tortoise was 255 years, but some may

have lived to be twice that age.

The Rougheye Rockfish

The rougheye rockfish just sounds

defiant. In fact, I'd include a few more

desciptions-- like riptide, rugged,

rumblin', radical and ravin'-- in its name,

but that would probably remind you too

much of that douchebag surfer-guy who

smoked a joint with your sister ten years

ago. And, just like that surfer-guy, the

rockfish is incredibly ugly but makes up

for it by being defiant of everything.

Including mortality. A rougheye

rockfish, which is a functionally

immortal animal, can live to be 200

years old or more, unless some guy with

a fishing-pole manages to break it of its

persistent addiction to life.

The Immortal Jellyfish

The name says all. When the immortal

jellyfish gets tired of being a sexually

mature adult, it can decide to be a

polyp-- that is, a baby-- again. To do this,

the jellyfish (technically a medusa) turns

itself inside-out, then re-absorbs its

tentacles and other dangly-bits. It then

land in its grave (or birth site)

somewhere in the sand and becomes a

colony of tiny little polyps. It's like your

grandpa deciding that he's going to go to

bed and turn into a few dozen fetuses--

only the immortal jellyfish doesn't have

dementia and actually will follow

through on its threat.

The Hydra

The hydra is a nearly

immortal animal, but what it lacks in size

it makes up for in stamina

Hydras are actually

remarkably efficient predators; they

release an explosion of neurotoxins into

their prey, paralyze it, and then consume

the animal whole. Every single cell in the

hydra's tiny body is constantly dividing

and rejuvenating, so any injured,

polluted or defective cells are diluted by

the thousands of others. Because they

are constantly replenishing their living

cells, hydras do not age at all-- ever.