First of all, stats from the 1E monster manual (I know there were some 2E stats, I’ll get those later if they’re notably different):
NO. APPEARING: 1-6
ARMOR CLASS: 5
HIT DICE: 30
% IN LAIR: Nil
TREASURE TYPE: Nil
NO. OF ATTACKS: 1
SPECIAL ATTACKS: Nil
SPECIAL DEFENSES: Nil
MAGIC RESISTANCE: Standard
SIZE: L (70’ long)
PSIONIC ABILITY: Nil
Attack/Defense Modes: Nil
The thunder-lizard is a 40 ton plant-eater found near marshes and lakes. The creature spends much of his time in shallow water to support his bulk. It moves to deep water to avoid carnivores. Apatosaurus ignores small things, but it is prone to step on anything in its way (doing 4-40 points of damage).
Hey, I thought I heard somewhere that that “support bulk in water” thing was so much BS, because it uses its tail for balance. Feel free to inject as much current scientific theory into this as you like, but let’s not get too bogged down in science – it’s just a game, after all.
And here is demiurge’s version:
Dinosaur, Apatosaurus (Brontosaurus)
Hit Dice: 20d8+166 (256 hp)
Speed: 20ft (4 squares)
Armor Class: 12 (-8 size, +10 natural), touch 2, flat-footed 12
Base Attack/Grapple: +15/+43
Attack: Tail slam +19 melee (3d8+18 plus thunderous snap)
Full Attack: Tail slam +19 melee (3d8+18 plus thunderous snap)
Special Attacks: Thunderous snap, trample 6d8+18
Special Qualities: Low-light vision, scent
Saves: Fort +23, Ref +12, Will +8
Abilities: Str 34, Dex 11, Con 27, Int 1, Wis 14, Cha 10
Skills: Listen +12, Spot +19
Feats: Alertness, Diehard, Endurance, Great Fortitude, Toughness (x2)
Environment: Warm forests, plains and hills
Organization: Solitary or pair
Challenge Rating: 10
Alignment: Always neutral
Advancement: 21-60 HD (Colossal)
Level Advancement: -
This massive quadruped has a very long neck and tail, a horse-like head, a wrinkled, elephantine hide and a small row of colorful spines lining its back, like those of an iguana.
The apatosaurs are the most common species of sauropod, the unbelievably large long-necked dinosaurs.
Although they vary in size, most apatosaurs are between 70 and 80 feet in length. They are solitary, unlike their relatives Diplodocus and Seismosaurus. They feed on low-lying foliage with their long necks, and can rear up on their hind legs and tail to reach the tops of trees.
Apatosaurs are so large that they have few natural enemies, besides allosaurs and megalosaurs hunting in packs. If directly threatened, they lash out with their powerful tails, but are capable of merely walking over most opponents.
Thunderous Snap (Ex): Although they are ponderous, an apatosaurus’ whip-like tail can move faster than sound. Any creature struck by an apatosaurus’ tail slam must make a Fortitude save (DC 28) or be stunned for 1d4 rounds and deafened for 1d4 minutes. On a successful save, the creature is merely deafened for 1d4 minutes. The save DC is Constitution based.
Trample (Ex): An apatosaurus can literally run over any creatures in its way that are of Gargantuan or smaller size. Creatures trampled must make a Reflex save (DC 32 half) or take 6d8+18 damage. The save DC is Strength based.