[Commissioned by @glarnboudin, who wanted a retro-rex with cinematic abilities. The original “Dynamosaurus” is a nomen invalidum, given to a chimera of Tyrannosaurus and nodosaur bones. I went with a magical beast given my predilection for retrosaurs as magically enhanced or created dinosaurs.]
Dynamosaurus
CR 12 N Magical Beast
This massive bipedal reptile is dominated by a huge head bristling with oversized teeth. Its arms are small in comparison, and its tail is broad and powerful. Armored scutes cover its back and body.
Augmented through magical enhancements and selective breeding, a dynamosaurus is a tyrannosaurus exaggerated and amplified. They are ultimate predatory beasts, their inherent instincts sharpened into a killing machine. Although they originated in arcane laboratories, dynamosauruses have escaped captivity and entered the wild, where they threaten to destabilize ecosystems with their lust for violence and hunger for meat.
The ground shakes as a dynamosaurus moves, and their very presence incites lesser creatures to panic. Those that are not already affected by its frightful presence are intimidated with its awful roar, and a dynamosaurus will frequently target fleeing creatures for the sheer joy of the chase. Their teeth can shear through solid bone, and the bony plates that protect their vital organs keep them from being felled by a lucky shot from prey. One of the few things that can kill a dynamosaurus is another dynamosaurus. Although they sometimes travel in groups, these are fractious alliances that can turn competitive in a blink.
A dynamosaurus is as long as a mundane tyrannosaur, averaging over forty feet long, but their musclebound frames and bony armor increase their weight.
Dynamosaurus CR 12
XP 19,200
N Gargantuan magical beast
Init +4; Senses darkvision 60 ft., low-light vision, Perception +25, scent
Aura frightful presence (60 ft., DC 21)
Defense
AC 23, touch 6, flat-footed 23 (-4 size, +17 natural)
hp 207 (18d10+108)
Fort +15, Ref +9, Will +12
DR 3/-
Defensive Abilities ferocity, fortification (50%)
Offense
Speed 50 ft.
Melee bite +28 (4d8+26/19-20 plus grab)
Space 20 ft., Reach 20 ft.
Special Attacks crushing critical, swallow whole (2d8+13, AC 18, 20 hp), terrible roar, thrash, trample (DC 32, 2d8+19)
Statistics
Str 36, Dex 11, Con 23, Int 1, Wis 18, Cha 14
Base Atk +18; CMB +33 (+37 grapple); CMD 43
Feats Dazzling Display (B), Improved Critical (bite), Improved Initiative, Intimidating Prowess, Iron Will, Power Attack, Shatter Defenses, Vital Strike, Weapon Focus (bite)
Skills Intimidate +29, Perception +21, Survival +10 (+18 when following tracks); Racial Modifiers +8 Intimidate, +8 Perception, +8 Survival following tracks
SQ powerful bite
Ecology
Environment warm forest and plains
Organization solitary, pair or pack (3-6)
Treasure none
Special Abilities
Crushing Critical (Ex) A creature struck by a critical hit from a dynamosaurus must succeed a DC 32 Fortitude save or take 1d6 points of Str drain. Creatures without a skeletal system are immune to this effect. The save DC is Strength based.
Powerful Bite (Ex) A dynamosaurus applies twice its Strength bonus to its bite damage.
Terrible Roar (Ex) A dynamosaurus can use its Dazzling Display feat as a move action.
Thrash (Ex) A creature grappled by a dynamosaurus must succeed a DC 23 Fortitude save or be stunned for 1d3 rounds. This save DC is Constitution based.
