Hippoctopus!

[The Demented One]

Hippoctopus
Size/Type: Huge Magical Beast
Hit Dice: 6d10+18 (51 hp)
Initiative: +3
Speed: 30 ft. (6 squares), swim 50 ft.
Armor Class: 19 (-2 size, -1 Dex, +12 natural), touch 7, flatfooted 19
Base Attack/Grapple: +6/+21
Attack: Bite +12 melee (2d6+7) or Tentacle +6 melee (1d8+3)
Full Attack: Bite +12 melee (2d6+7) and 4 Tentacle +6 melee (1d8+3)
Space/Reach: 15 ft./10 ft. (20 ft. with tentacles)
Special Attacks: Bewildering presence, breath weapon, constrict 1d8+3, improved grab
Special Qualities: Darkvision 60 ft., hold breath, low-light vision
Saves: Fort +5, Ref +5, Will +4
Abilities: Str 24, Dex 8, Con 16, Int 3, Wis 14, Cha 10
Skills: Hide +7, Listen +5, Spot +5, Swim +18
Feats: Improved Initiative, Iron Will, Weapon Focus (Bite)
Environment: Any Aquatic
Organization: Solitary
Challenge Rating: 5
Treasure: None
Alignment: Usually True Neutral
Advancement: 7-15 (Huge), 16-20 (Gargantuan)
Level Adjustment: +6 (cohort)

Not all ideas are as good in practice as they are in theory. For example, using magic to combine two feared and powerful beasts to create an even more powerful monster is, in theory, a good idea. However, when the two beasts you combine are a hippopotamus and an octopus...well, the end result is a Hippoctopus. While it is a powerful creature to be feared, the Hippoctopus is so awkward and bizarre a creature that few mages have ever bothered to create one. Those that do, however, find themselves in possession of a powerful beast, capable of fighting both on land and below water. Even if it is a bit silly-looking. A Hippoctopus resembles a garden-variety hippo, but its skin is like that of an octopus, constantly changing colors and textures and textures to match that of its surroundings. In addition, four long tentacles stretch out from the underbelly of the Hippoctopus, constantly scouring its surroundings for food.

Bewildering Presence (Ex)
Hippoctopi are bizarre, bizarre creatures. Any creature that sees a Hippoctopus must make a DC 16 Will save or be fascinated for 1 round, trying to tell whether or not what they’re seeing is real. A creature can only be affected once by this ability. The save is Constitution-based.

Breath Weapon (Ex)
As a standard action, a Hippoctopus can breath out a 45 ft. cone of ink. All creatures caught in the cone must make a DC 16 Reflex save or be covered in ink. A creature covered in a Hippoctopus’s slippery ink suffers several ill effects. Each round, it must make another Reflex save or slip, falling prone. In addition, the slick ink coating its hands makes holding items difficult. When it is initially covered in ink, the inked creature must make another Reflex save for each item he is holding, or drop it at his feet. If he tries to pick up an item while covered in ink, he must make another save or drop it. The ink dries up after 1d6 rounds, and can be washed off with water as a full-round action. Once a Hippoctopus has used its breath weapon, it must wait 5 rounds before it can use it again.

Constrict (Ex)
A Hippoctopus deals 1d8+3 points of damage with a successful grapple check.

Improved Grab (Rx)
To use this ability, a Hippoctopus must hit an opponent of any Huge size or smaller with at least two of its tentacle attacks. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and can constrict.

Hold Breath (Ex)
A Hippoctopus can hold its breath for a number of rounds equal to 8 × its Constitution score before it risks drowning.

Skills
A Hippoctopus as a +16 racial bonus on Hide checks. In addition, a Hippoctopus has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

[Krimm_Blackleaf]

I don't know what it is that you're smoking, but I want some.

[Valairn]

Consider this *yoinked*! :-D This is absolutely fantastic.

[AugustNights]

Why does it have a +16 racial bonus to hide?
How could something that odd hide naturally that well?

[Innis Cabal]

How else is it still alive?

[Krimm_Blackleaf]

Why does it have a +16 racial bonus to hide?
How could something that odd hide naturally that well?

Because of it's skin being like that of a squids, i.e. being able to change to any color at will.

[The Demented One]

Yeah, I've always been captivated by that aspect of the octopus kingdom after seeing a really cool discovery channel bit on it when I was about 5. Not just camouflage, their skin's texture can actually change to match whatever's around.

[bosssmiley]

I'm put in mind of that weird hippo-sized ambush predator from Lords of Madness. You know, the bizarre Illithid-derived thing that catches prey by projecting illusions. Originally saw print in a Dragon magazine (#160?) IIRC.