Specifically, and by specifically I mean specifically, and by and by I mean and by,

Susie is a type of sea slug called a nudibranch.

There are around 3,000 freaky species of nudibranchs, but they come in two basic body plans.

One body plan can be seen in the earlid nudibranchs.

They can look a bit like claymation pubic hair, or like a porcupine rolled around in candy corn.

Their backs are covered with floppy, floppy, spiky things called serrata.

These serrata are extensions of their digestive system, because why not?

But they also assist in breathing.

The other body plan belongs to the dorid nudibranch.

It is the more sluggy of the two.

Dorid nudibranchs have a sturdy, fleshy, fleshy covering called a mantle.

The mantle can sometimes look like a frilly skirt, or perhaps a fashionable poncho.

Some species, like the Spanish dancer nudibranch, can use this skirt to swim.

Sort of.

Some other nudibranchs also try the swimmy-swimmy, but in most cases it looks a bit like a muppet simultaneously auditioning for the part of the F, U, and N in a Sesame Street production brought to you by the word fun.

It does actually look fun to swim like that, like sneezing in outer space.

Up front, nudibranchs have two rhinophores, which are kind of like nostrils that have been turned inside out.

Much like our noses can pick up the chemical signals of a fart wafting in the air, these rhinophores can pick up chemical signals in the water.

This is important because their eyes totally suck.

They are very tiny and can only sense dark and light.

Like a colorblind machinist in a Skittles factory, the nudibranch is unable to appreciate the beauty of its own decoration.

This one looks a bit like a landspeeder.

Whoa!

Except near the back where you would expect the peoples to sit.

That is a plume of gills that encircle their anus.

These gills are beautifully folded structures that maximize surface area to extract oxygen from the surrounding water.

These allow the dorid nudibranch to breathe right next to its anus.

Before you judge, however, to the nudibranch this body plan might feel like an upgrade.

To understand this, let's look at some nudibranchs when they are babies.

Little baby nudibranchs look a lot like snails.

They have a shell and some even form an operculum, a little trapdoor for their hidey hole.

A long time ago, the shelled ancestor of snails and slugs got into some freaky sh** called torsion.

Torsion is a twisted change in body plan.

To understand this, imagine if you laid down on your stomach and arched your back.

Then you grabbed your left foot with your right hand and your right foot with your left hand.

Now imagine twisting really hard so that your butt faces upwards and is right over your face.

This is the first yoga pose they teach you when you arrive in hell.

Snails live out their lives cheerfully with this arrangement. Don't ask why.

Every time you ask why, evolution adds or removes a nipple from a cat. Look it up.

However, millions of years ago, after a night of eating jalapeno chili con carne, the ancestor of the nudibranch had enough of this head-up-your-butt.

As it transitions to its juvenile state, the baby nudibranch loses its shell, untwists, and does its best to put all of its organs back in some semblance of order.

That is to say that the nudibranch is a bit of an unsnailed snail.

And at least its mouth and nose have a bit of distance from its gill-ringed anus.

And yes, that one does look like a Pikachu that got busy with a Swiffer.

The nudibranch's mouthparts are under its front parts, right between a befingered mustachio of two feeding tentacles that can help it feel around for food.

They eat a variety of animals, many of which, like colonial tunicates, bryzoans, and hydroids, are animals that look like plants.

Because the ocean is weird.

They are among the cutest carnivorous predators, and will even eat other slugs and nudibranchs.

This one's eating a slug called a sea hare, because apparently it looks like a rabbit.

A rabbit who's squirt-farting purple ink because he's seriously f***ed.

If we speed it up, it looks like he's slurping a noodle.

They eat with a beak and a radula, which is basically a tongue with teeth on it.

Which is crazy.

Don't French kiss a nudibranch.

You'll die.

Here we see an anemone being hunted by a rainbow nudibranch, which does not look like a rainbow at all.

More like a curtain that a cat got to.

But it strikes with the vigor of a proctologist who lost a wedding ring.

That's like trying to tongue-sponge the crumbs out of the bottom of a can of Pringles.

One group of nudibranchs in the genus Melibe has evolved a different feeding strategy.

It has traded in its tooth-tongue radula for a head in the shape of a Venus flytrap.

It uses its head like a seafloor pooper-scooper.

Like if you used your hoodie to eat a shrimp taco.

A skeleton shrimp taco.

Lacking a shell, sea slugs, including nudibranchs and this spotted sea hare, which does not look like a rabbit, must get creative when it comes to defense from predation.

Some have evolved to be very good at camouflage.

You see these cows? I tricked you.

They're not cows, they're nudibranchs.

You thought they were cows.

You must feel like a real dum-dum man.

This one is perfectly camouflaged as an old man with his hands behind his back inspecting his garden.

Damn slugs eating my azaleas.

That's irony.

You better stop or I will assault you.

That's a dad joke.

Some nudibranchs, like this ghost Melibe, have gotten so good at hiding they're transparent.

Mostly.

Fortunately, their less transparent insides resemble a bunch of floaty-floaty sea garbage.

Well played, Melibe.

Some of the animals that nudibranchs eat contain toxins.

Some dorid nudibranchs incorporate these toxins into their body parts, so they don't taste good.

The defense-after-you've-been-bitten approach is a little late in the process for me.

But it has been proposed that the bright coloring of some nudibranchs has evolved as a warning sign to potential predators.

Scary clown says run away.

Some elid nudibranchs take this one step further.

They eat animals that have specialized stinging cells called nematocysts.

Glaucus atlanticus, for example, will eat the blue-bottle man-of-war jellyfish.

The jellyfish, however, contains thousands of these nematocysts, coiled up and ready to fire when disturbed.

Much like butt-smuggling hand grenades, elid nudibranchs ingest these cells and transport the immature, unexploded ones out to the tips of their serrata, where they can use them for their own stinging defense.

It's pretty cool.

Look at this one.

They're using like a little laser.

It's like if when you ate pop rocks, you could transport them to the tip of your...

fingers, you perv.

For a tingly handshake.

The blue-dragon nudibranch also steals cells.

Instead of stingers, it steals zooxanthellae, microscopic plants, incorporating them into its body and using them to produce food from sunlight.

You know who else does this?

This little guy.

It's a saclogosan sea slug, not a nudibranch, but who cares?

I love it. It's cuter than puppies.

It is mating season, and first the nudibranchs have to find each other.

They are often solitary and spread out.

Finding the slime trail of another nudibranch is worth following up on.

Many nudibranchs do this trailing behavior, following another's slime trail until they're right up in it.

And I mean right up in it.

But not really right up in it.

The nudibranch's genitals are located up near its head on the right side of its body, because of course they are.

This means that they have to position themselves so their right sides line up.

Think of it like a high five, but with no hands, and four genitals.

That's right, four.

Nudibranchs are hermaphrodites, meaning that each is equipped with both a penis and a vagina.

I know what you're thinking.

If I had that kind of luggage, I'd pack it myself.

Sure, once in a while a researcher will find a nudibranch's penis inside of its own vagina.

Don't judge, it's a lot to keep track of.

And quite frankly, if it's in the way flopping around out there, it's the obvious place to put it.

I mean, why aren't our pants pockets shaped like gloves? There's mysteries in this world.

Doesn't mean you're trying to self-fertilize, just some healthy curiosity.

While mating, both nudibranchs put their penises inside the other's vagina, and both are fertilized in the process.

Now, I'm not sure if you can see it, but if you squint, you might notice that the nudibranch penis has a bit of a barbed hook sort of shape.

That can make uncoupling a bit of a bitch.

So much so that the chromodorus reticulata just lets it break off and grow back again.

It's one way to do it.

After mating, it is time for the nudibranch to deposit its fertilized eggs.

It does so in a series of beautiful strings and rosettes, adorning the shapes of the ocean floor.

Thousands of little eggs that will become thousands of little babies.

And the circle of life continues.

Listen, sometimes feeling safe in a shell isn't worth having your insides all twisted up.

Or having an ass on your head.

That might be too on the nose.

I didn't mean like an ass on your nose, that's, I mean, too literal.

The point is, sometimes you have to take a risk.

Get out of that shell and untwist.

Who knows what kind of crazy, beautiful thing you might become.

Ist. Sorry, it felt like it should rhyme.

And that is how the nudibranch do.