Come on, come on, come on.

Right over here guys.

It's huge.

Oh my gosh.

Look at the size of that thing.

Wow.

Can I pick it up?

You can.

Whoa, look at that.

All right, here we go.

Oh my gosh is it slimy.

(dramatic music)

If there is one ecosystem on the planet

that is constantly changing,

it has to be the tide pools.

With every single rising and falling of the tide,

new waves crash upon the rocks,

and alter the placement of plants and animals.

Along the coast of California,

there are a slew of creatures that you can find,

if you know exactly where to look.

A little striped crab right here.

Oh got it.

There's definitely no shortage of crabs

out here in these tide pools.

However, navigating this terrain

can be difficult,

because most of the rocks are wet and slippery.

One of the toughest things so far for me,

in filming beyond the tide has been the terrain.

I'm used to swamps and deserts.

Everything here is rocky and slippery.

It's all cover in a layer of,

I guess, it's some sort of algae.

And using a lot of eye-foot coordination,

because I'm looking for creatures,

and every step I take,

your foot might slip off of something,

and these rocks are extremely jagged.

Really easy to get hurt out here.

And I'm sure for you Mark,

is even more difficult.

Right now you're balancing on these rocks

just trying to get these shots.

Show everybody at home.

It isn't easy, is it?

Nope.

All right, well let's keep going this way

and see what we can find.

Watch your footing.

Oh, yup, see there you go.

I'm usually pretty good

at finding animals in the field.

But sometimes a wildlife expert joins us

to help locate the species that can be

very difficult to find.

Today, I'm back out with tide pool expert Aron Sanchez,

who's been exploring these Southern California pools

his entire life,

and our goal is to locate a giant sea slug.

All right Aron, so we're here at the tide pools,

and we're looking for slugs.

What should I be keeping my eye out for?

Well Coyote, these slugs

are going to be pretty hard to miss.

They're actually the largest sea slug on the planet.

They come to these rocky shores here

to mate and lay their eggs.

Okay, when you say the largest,

do you mean like five to six inches in length,

or are we talking bigger?

-We're talking probably almost

a little bit less than three feet.

A three foot slug?

So it's going to be pretty hard to miss?

Yeah.

All right, let's start searching.

The search was on,

and I was confident that I could

come across one of these giants.

I mean, if they're as big as Aron says they are,

spotting one should be simple.

Right?

Hi, we've been searching for

about 45 minutes now

through all these layered rocks.

I don't know, Aron said it was going to be easy.

Nothing yet.

We continue to search,

over jagged outcrops, in crevasses,

through knee deep pools, and even under rocks.

I would say the odds of finding one of these slugs

are slim to none.

Tides really coming in.

Yeah, it's coming in big time,

and all I've seen is crabs, crabs, crabs.

Hermit crabs, striped crabs, purple shore crabs,

no giant slugs.

With the tides

starting to come back in,

it was looking like our search for the giant sea slug

was coming to an end,

but if anyone knows how to find a sea creature,

it's definitely Aron.

- Searching, searching.

No big slugs.

Yeah.

Oh you got one.

Come on, come on, come on.

Right over here guys.

It's huge.

Oh my gosh.

Look at the size of that thing.

Wow, dude, yes.

Well that was one heck of a search,

and there it is.

Can I pick it up?

You can.

It's totally safe.

And it's not going to ink me.

Might be a little slimy but that's it.

Whoa, look at that.

Oh my gosh is it slimy.

Oh, look at that slug.

Oh my gosh it is heavy.

Geez, this thing must be about

almost 10 pounds I would guess.

Is that a big one Aron?

It's a pretty good size, yeah.

It's one of the bigger ones I've seen.

I'm going to let it stretch out on my arm,

see if we can get it to fully elongate itself.

Oh my gosh, it is so slimy.

All right, now tell us about this slug, Aron.

Well Coyote, what he's wrapping around his arm right now

is actually his muscular foot.

He uses that to get around.

I can feel him gripping on to my arm.

I mean, I can feel him actually wrapping around me.

And I can feel his little tongue under there.

Can't bite right?

No, these guys are vegetarians.

They mostly eat algae and kelp.

And it does have an internal shell, correct?

Where it has all of it's organs?

It does have an internal shell.

It's kind of soft and made of protein.

And that is actually what these extensions

of its foot, called parapodium, are protecting.

I can see why there's no way you would miss

stumbling upon one of these.

I have to admit, I was just over there talking to Mark,

I literally said, "I'm really doubting our chances

of finding one of these slugs."

All we've seen all day is crabs

and smaller little brown sea hares.

Which by the way, we should grab one of those.

Isn't there one over here?

Let's see it next to each other.

Yeah, all right you got

one of those brown sea hares?

Okay, so this is cool,

showing the comparison of the giant black sea slug,

next to the much smaller brown sea slug.

And they're both called sea hares,

because as you can see

those tentacles sticking up in the air,

in the front of the head,

look like rabbit's ears.

I thought the brown sea hare was big.

Yeah, seriously there is no mistaking

the difference between these two species.

Wow, that thing is absolutely massive.

It weighs about 10 pounds,

and fully stretched out it's about two feet in length.

That is crazy, and it is so unbelievably slippery.

It's actually really hard to hold on to it.

And my hands and arms are now covered

in a slippery mucus.

Now are they toxic in any way?

No, they're not.

Okay, so I'm in no danger right now?

So they don't bite.

They're not toxic.

They're just slimy and alien looking.

So how do these defend themselves against predators?

Well you know, these guys don't have

as many predators as the California sea hare,

probably due to their size.

So they would generally just stick to where they are,

and they're going to be pretty well hidden in these rocks.

I can't even imagine what would want to try to eat this.

It's just so amazing how big this slug is.

When you said to me, "Yeah, we're going to go out.

"We're going to catch a giant slug."

I honestly didn't believe you.

When you said they could

grow to be about two feet in length.

And until I actually had this animal in my hand,

really on my arm,

I didn't believe it.

This is absolutely amazing.

Well Aron, thank you so much for having us out today,

to explore the tide pools her at San Pedro.

I think there's no question about it.

This is one big black slug.

I'm Coyote Peterson.

Be brave.

Stay wild.

We'll see you on the next adventure.

We gently place these

two slimy slugs back into their respective pools,

and watched as they slowly returned to the wild.

I think it's fair to say that these creatures are as primordial as it gets.

And while they may be incredibly bizarre looking,

they are an important part of the tide pool ecosystem.

Make sure to check out some of Aron's tide pool photography

by visiting his Instagram account @Waterbod,

or his website, waterbodymedia.com.

If you thought this adventure was exciting,

make sure to go back and watch my close encounter

with the yellow bellied sea snake.

And don't forget, subscribe to the brave wilderness channel

so you can join me and the crew on this season of

Beyond the Tide.

There's no question about it,

this is the most lethal snake species I have ever handled.