monster Dunkleosteus (Dinichthys)

Originally Posted by Shade of the En World forums. On this Thread
Dunkleosteus terreli, a placoderm from the Devonian,
pencil drawing, digital coloring March 11, 2008 ArthurWeasley

This massive fish is entirely covered with huge bony plates, which extend over its jaws to form a horny beak.

A dinicthys is around 30 feet long, but they grow throughout their lives, resulting in some frightfully huge specimens. Although driven into extinction in most areas by the faster and keener-sensed sharks, dinicthys thrive in warm costal waters. They are capable of living in much shallower water than sharks even of smaller sizes, and feed on fish and animals venturing into their territories- including humanoids.

Dinicthys
Huge animal (Aquatic)
Hit Dice 10d8+50 (95 hp)
Initiative +3
Speed Swim 40 ft. (12 squares)
Armor Class 22 (-2 size, -1 Dexterity, +15 natural), touch 7, flat-footed 22
Base Attack/Grapple +7/+23
Attack Bite +13 melee (3d6+12)
Full Attack Bite +13 melee (3d6+12)
Space/Reach 15 ft./10 ft.
Special Abilities Augmented critical,
improved grab, swallow whole, vortex maw
Special Qualities Low-Light Vision
Saves Fort +12, Ref +6,
Will +5
Abilities Strength 26, Dexterity 8, Constitution
21, Intelligence 1, Wisdom 14, Charisma 2
Skills Move Silently +9, Spot +8, Swim +16
Feats Endurance, Improved Initiative, Power
Attack
, Skill Focus (Move Silently)
Environment Warm aquatic
Organization Solitary
Challenge Rating 7
Treasure None
Alignment Always neutral
Advancement 11-20 HD (Huge), 21-30 HD (Gargantuan)

COMBAT

In combat, a dinicthys grabs an unsuspecting prey item and either swallows it or rips it into bloody chunks. Its bite is as powerful as that of a tyrannosaurus, and can shear through steel.

Augmented Critical (Ex): A dinicthys’s bite threatens a critical hit on a natural attack roll of 18–20, dealing triple damage on a successful critical hit.

Improved Grab (Ex): In order to use this ability, a dinicthys must hit with a bite attack. If it hits, it can make a grapple check as a free action without provoking an attack of opportunity. If it gets a hold, it deals automatic bite damage each round and can swallow its opponent whole.

Swallow Whole (Ex): By making a successful grapple check, a dinicthys may swallow a held foe at least one size smaller than itself whole. Once swallowed, a victim takes 2d8+8 points of bludgeoning damage plus 8 acid damage every round until it escapes or dies. A successful grapple check allows the creature to Climb out of the stomach and into the dinicthys’s mouth, where another grapple check is required to get free. Alternatively, the swallowed creature can escape by cutting its way out with either claws or a light slashing or piecing weapon. Dealing at least 30 points of damage (AC 13) in this fashion allows the creature to escape. Once a single swallowed creature exits, muscular action closes the whole; another  swallowed creature must cut its way out as well. A dinicthys’s stomach can
hold 2 Medium-sized, 8 Small, 32 Tiny or 128 Diminutive or smaller creatures.

Vortex Maw (Ex): A dinicthys can open its mouth so quickly that it creates a powerful suction. All creatures within a 30-foot cone must make Strength checks opposed by the dinicthys’s Strength check (+16 for a standard dinicthys), with the same modifiers as a bull rush. If the dinicthys beats a creature’s Strength check result, it pulls the victim 5 feet closer to its jaws. For each 5 points by which its check result is greater than a victim’s check result, the dinicthys pulls the victim an additional 5 feet closer. The victim provokes attacks of opportunity if it is moved.

Skills: A dinicthys has a +8 racial bonus on any Swim check to perform a 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.

Originally appeared in Monster Manual (1977).