Converting prehistoric creatures

[Shade]

We've got multiple votes for Huge. Care to sell us on Large, Cleon?

 

[Cleon]

We've got multiple votes for Huge. Care to sell us on Large, Cleon?

If you like.

Argument #1
Roll up! Roll up! Buy your compact sized pliosaurs here! Half the length of Huge and half the fuss! With our new compact breeds you enjoy reduced feed bills and need never fear them outgrowing your monster infested moat!

Argument #2
The Dragon magazine Dinosaurs article says "they may be treated as crocodilians of 5 HD or more".

That Dragon Magazine's article on Crocodilians has the following HD/Damage/Size table:

Hit Dice Damage Size
1 hp Nil S(to 3)
¼ 1 S(4)
½ 1d2 S(5)
1 1d4 M(6)
2 1d4+1 M(7)
3 2d4 L(8-9)
4 2d6 L(10-11)
5-6 2d8 L(12-15)
7-8 2d10 L(16-25)
9-10 3d8 L(26-35)
11-12 3d10 L(36-45)
13-14 3d12 L(46-55)

As you can see, the 5 Hit Dice crocodilian is 12-15 feet long, which is a better fit to Large than Huge.

Argument #3
Your SRD Crocodile is 3 HD and Medium, with 4-5 HD (Medium) Advancement, so according yo the official 3rd edition rules a 5 HD crocodilian is smaller than Large. That means I'm being generous making them Large rather than Huge...

Argument #4
The fossil record indicates the largest species of Pliosaur could reach 50 feet long (e.g. "Predator X"), but the smaller species could be considerably smaller, e.g. Macroplata (~15 feet), Meyerasaurus and Peloneustes (~10 to 12 feet) or the modest Thalassiodracon (which was only 5 to 7 feet long).

Argument #5
Even if every Pliosaur in the D&D seas grew up to be Huge- or larger monsters, they'll be smaller when they were younger. A juvenile pliosaur would probably hunt much like an adult, so the DM would probably use the same stats for half-grown Kronosaurus as for a full-grown Macroplata, since both are about 15 feet long.

Argument #6
I was assuming we'd be having seperate stat blocks for each size category, e.g. Generic Large Pliosaur, Generic Huge Pliosaur, Generic Gargantuan Pliosaur et cetera.

 

[freyar]

Not sure we need separate statblocks, given that we already have larger versions...

But I am convinced that we should start with Large, advancing well into Huge, just based on the real-world sizes of some of these things.

 

[Cleon]

Not sure we need separate statblocks, given that we already have larger versions...

But I am convinced that we should start with Large, advancing well into Huge, just based on the real-world sizes of some of these things.

I think the advancement should go up to Gargantuan, since the largest Pliosaurs were 50+ feet.

They could go like this:

Generic Large Pliosaur 10-12 feet long (5 Hit Dice)
Generic Huge Pliosaur 20-25 feet long (10 Hit Dice)
Generic Gargantuan Pliosaur 40-50 feet long (20 Hit Dice)

That would fit with the SRD Elasmosaurus which is 10 HD and Huge, and reaches Gargantuan at 21+ HD.

Generic Pliosaur #1: 5-9 HD (Large); 10-20 HD (Huge); 21-30 HD (Gargantuan)

Contrariwise, if they are based on "Crocodilian" stats we should also consider the SRD Giant Crocodile, which is 7 HD and Huge. Also, we've also got a big Pliosaur conversion in Enworld, the Kronosaurus, which is Gargantuan but only has 17 Hit Dice.

That suggests it may have a lower HD range, maybe something like:

Generic Pliosaur #2: 5-8 HD (Large); 9-16 HD (Huge); 17-25 HD (Gargantuan)

Liopleurodon has official stats in Dragon #318, It is a Colossal 80+ foot creature with 38 Hit Dice, which is much larger than known fossil evidence supports.

If we expand our Pliosaurs HD and size values to Colossal, you'll see that a 38 HD Liopleurodon is a better fit to the "lower HD" Pliosaur #2:

Expanded Generic Pliosaur #1: 5-9 HD (Large); 10-20 HD (Huge); 21-41? HD (Gargantuan); 42-75? HD (Colossal)
Expanded Generic Pliosaur #2: 5-8 HD (Large); 9-16 HD (Huge); 17-32 HD (Gargantuan); 33-75 HD (Colossal)

 

[Cleon]

Oh, and I also posted a homebrew Pliosaurus which is posted here.

 

[RavinRay]

I think the advancement should go up to Gargantuan, since the largest Pliosaurs were 50+ feet.

There's some debate as to whether a recently describe giant Pliosaurus is actually either Kronosaurus or Liopluerodon, but in any case it demonstrates that this genus can be scaled up, as per the rest of Cleon's post.

Liopleurodon has official stats in Dragon #318, It is a Colossal 80+ foot creature with 38 Hit Dice, which is much larger than known fossil evidence supports.

True, an 80 foot pliosaur, has, as of this writing at least, not yet been discovered. If it does happen, it would be another case of life imitating art after the discovery of more complete Utahraptor fossil following Spielberg's decision to scale up Velociraptor in the Jurassic Park movie, though it had already been named from an earlier pre-movie find.

 

[Cleon]

There's some debate as to whether a recently describe giant Pliosaurus is actually either Kronosaurus or Liopluerodon, but in any case it demonstrates that this genus can be scaled up, as per the rest of Cleon's post.

True, an 80 foot pliosaur, has, as of this writing at least, not yet been discovered. If it does happen, it would be another case of life imitating art after the discovery of more complete Utahraptor fossil following Spielberg's decision to scale up Velociraptor in the Jurassic Park movie, though it had already been named from an earlier pre-movie find.

There are several potential 50+ foot giant Pliosaur fossils, and I haven't heard that any have been clearly identified yet. What genus they are doesn't matter much for the purposes of this thread. As you say, so long as it establishes Gargantuan examples existed we should include them in our Generic Pliosaur stats.

As for the 80-foot Liopleurodon, well it is a fantasy game so we might as well include a larger-than-supported-by-the-fossil-record example in the stats. It's no more a stretch than some of the size advancements WotC gave dinosaurs - such as Tyrannosaurus rex advancing to Gargantuan.

So, where are you on the size/HD question?

I'm starting to lean towards 10 Hit Dice for the Huge Pliosaur, because I don't want them to have fewer HD than the SRD Elasmosaurus, which should make a "more official" baseline than a Crocodile or Giant Crocodile.

I guess we could tweak the HD scale a bit to fit in the 38 HD Colossal Liopleurodon, since that's also an official creature:

Expanded Generic Pliosaur #1: 5-9 HD (Large); 10-20 HD (Huge); 21-41? HD (Gargantuan); 42-75? HD (Colossal)
Expanded Generic Pliosaur #2: 5-8 HD (Large); 9-16 HD (Huge); 17-32 HD (Gargantuan); 33-75 HD (Colossal)
Expanded Generic Pliosaur #3: 5-9 HD (Large); 10-20 HD (Huge); 21-37 HD (Gargantuan); 38-75 HD (Colossal)

Hmm, I like that #3 progression, it's a decent fit to the available data points.

Also, what special abilities are we giving them - at the very least they need Keen Scent and Hold Breath.

I'm also wondering whether we can shoehorn in any Special Attacks - Improved Grab to seize prey, Worry to shake prey apart, Swallow Whole for smaller opponents, Burst of Speed to catch swift prey, Powerful Charge to make its underwater ambushes more devastating?

 

[Shade]

I prefer #3.

 

[Cleon]

I prefer #3.

So do I.

Might as well start on it.

We've got a number of official creatures to model the stats on - the SRD's Elasmosaurus and crocodiles, plus Dragon #318's Liopleurodon:

Liopleurodon (C) Str 46, Dex 10, Con 34, Int 2, Wis 16, Cha 13, 4d8 bite, NA +20
Elasmosaurus (H) Str 26, Dex 14, Con 22, Int 2, Wis 13, Cha 9, 2d8 bite, NA +3
Crocodile (M) Str 19, Dex 12, Con 17, Int 1, Wis 12, Cha 2, 1d8 bite, NA +4
Giant Crocodile (H) Str 27, Dex 12, Con 19, Int 1, Wis 12, Cha 2, 2d8 bite, NA +7

We'd need to change their size to Large for our base creature:


Large Versions
Liopleurodon Str 22, Dex 16, Con 22, Int 2, Wis 16, Cha 13, 1d10 bite, NA +8
Elasmosaurus Str 18, Dex 14, Con 18, Int 2, Wis 13, Cha 9, 1d10 bite, NA +0
Crocodile (M) Str 27, Dex 10, Con 21, Int 1, Wis 12, Cha 2, 2d6 bite, NA +6
G Crocodile (H) Str 19, Dex 14, Con 15, Int 1, Wis 12, Cha 2, 1d10 bite, NA +4

If we just average all four sets of numbers it works out:

Str 21½, Dex 13½, Con 21, Int 1½, Wis 13¼, Cha 6½, 1d10 bite, NA +4½

Hmm, I'm liking the Liopleurodon's Strength (which is also the average of the two Crocs) and the Elasmosaurus for the other stats.

1d10 seems too low for bite damage though. The Dragon #112 article gave 2d8 for the damage, so I'd peg it inbetween at 2d6, like an SRD Crocodile advanced one size. It should certainly have base damage more than an Elasmosaurus, since they have much bigger heads.

I'll start a Working Draft.

 

[Cleon]

Generic Pliosaur Working Draft

Pliosaur, Large
Large Animal
Hit Dice: 5d8+20 (42 hp)
Initiative: +2
Speed: 20 ft. (4 squares), swim 50 ft.
Armor Class: 15 (-1 size, +2 Dex, +4 natural), touch 11, flat-footed 13
Base Attack/Grapple: +3/+12
Attack: Bite +8 melee (1d10+9)
Full Attack: Bite +8 melee (1d10+9)
Space/Reach: 10 ft./5 ft.
Special Attacks: Improved grab, swallow whole, worry 2d8+12
Special Qualities: Keen scent, hold breath, low-light vision
Saves: Fort +10, Ref +6, Will +2
Abilities: Str 22, Dex 14, Con 18, Int 2, Wis 13, Cha 9
Skills: Listen +5, Spot +5, Swim +14
Feats: Great Fortitude, Weapon Focus (bite)
Environment: Warm aquatic
Organization: Solitary
Challenge Rating: 4
Treasure: None
Alignment: Always neutral
Advancement: 6-9 HD (Large)
Level Adjustment: —

Pliosaur, Huge
Huge Animal
Hit Dice: 10d8+60 (105 hp)
Initiative: +1
Speed: 10 ft. (2 squares), swim 50 ft.
Armor Class: 17 (-2 size, +1 Dex, +8 natural), touch 9, flat-footed 16
Base Attack/Grapple: +7/+25
Attack: Bite +16 melee (2d8+15/19-20)
Full Attack: Bite +16 melee (2d8+15/19-20)
Space/Reach: 15 ft./10 ft.
Special Attacks: Improved grab, swallow whole, worry 3d8+20
Special Qualities: Keen scent, hold breath, low-light vision
Saves: Fort +15, Ref +8, Will +4
Abilities: Str 30, Dex 12, Con 22, Int 2, Wis 13, Cha 9
Skills: Listen +6, Spot +9, Swim +18
Feats: Great Fortitude, Improved Critical (bite), Power Attack, Weapon Focus (bite)
Environment: Warm aquatic
Organization: Solitary
Challenge Rating: 7
Treasure: None
Alignment: Always neutral
Advancement: 11-20 HD (Huge)
Level Adjustment: —

Pliosaur, Gargantuan
Gargantuan Animal
Hit Dice: 21d8+219 (313 hp)
Initiative: +0
Speed: Swim 60 ft.
Armor Class: 19 (-4 size, +13 natural), touch 6, flat-footed 19
Base Attack/Grapple: +15/+41
Attack: Bite +24 melee (4d8+21/19-20)
Full Attack: Bite +24 melee (4d8+21/19-20)
Space/Reach: 20 ft./15 ft.
Special Attacks: Improved grab, swallow whole, worry 6d8+28
Special Qualities: Keen scent, hold breath, low-light vision
Saves: Fort +23, Ref +12, Will +8
Abilities: Str 38, Dex 10, Con 28, Int 2, Wis 13, Cha 9
Skills: Listen +8, Spot +18, Swim +22
Feats: Awesome Blow, Epic Toughness, Great Fortitude, Improved Bull Rush, Improved Critical (bite), Improved Natural Attack (bite), Power Attack, Weapon Focus (bite)
Environment: Warm aquatic
Organization: Solitary
Challenge Rating: 11
Treasure: None
Alignment: Always neutral
Advancement: 22-37 HD (Gargantuan)
Level Adjustment: —

Pliosaur, Colossal
Colossal Animal
Hit Dice: 38d8+546 (717 hp)
Initiative: +4
Speed: Swim 60 ft.
Armor Class: 22 (-8 size, +20 natural), touch 2, flat-footed 22
Base Attack/Grapple: +28/+62
Attack: Bite +39 melee (6d8+27/19-20)
Full Attack: Bite +39 melee (6d8+27/19-20)
Space/Reach: 30 ft./20 ft.
Special Attacks: Improved grab, swallow whole, worry 8d8+36
Special Qualities: Keen scent, hold breath, low-light vision
Saves: Fort +35, Ref +25, Will +17
Abilities: Str 46, Dex 10, Con 34, Int 2, Wis 13, Cha 9
Skills: Listen +13, Spot +30, Swim +26
Feats: Awesome Blow, Epic Reflexes, Epic Toughness × 3, Epic Will, Great Fortitude, Improved Bull Rush, Improved Critical (bite), Improved Initiative, Improved Natural Attack (bite), Power Attack, Weapon Focus (bite)
Environment: Warm aquatic
Organization: Solitary
Challenge Rating: 11
Treasure: None
Alignment: Always neutral
Advancement: 39-75 HD (Colossal)
Level Adjustment: —

This swimming reptile has a sleek body propelled by four powerful flippers and a comparatively short tail and neck. Its large head is dominated by long jaws filled with huge, conical teeth.

Pliosaurs are aquatic reptiles related to the long-necked plesiosaurs such as Elasmosaurus. While ordinary plesiosaurs had small heads and ate prey much smaller than themselves, pliosaurs used their mighty jaws to tackle bigger prey, including large fish, ammonites and other marine reptiles.

Known species of pliosaur ranged in size from as little as 5 feet long from nose to tail to at least 50 feet in length. A typical Large-sized pliosaur in between 10 and 12 feet long.

COMBAT

A pliosaur may try to eat creatures up to its own size, but prefers prey smaller than itself. The reptile usually charges an opponent and attempts to seize it in their jaws. Small and weak prey are normally swallowed whole once a pliosaur has them in its grip. It uses its worry special attack against more formidable prey, literally trying to shake its opponent into pieces.

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

Improved Grab (Ex): To use this ability, a pliosaur must hit an opponent of up to one size smaller with its bite attack. 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 try to swallow the foe the following round.

Keen Scent (Ex): A pliosaur can notice creatures by scent in a 180-foot radius, and can sense blood in the water at ranges of up to a mile.

Swallow Whole (Ex): A pliosaur can try to swallow a grabbed opponent of up to two sizes smaller by making a successful grapple check.

The swallowed creature takes 1d10+5 points of bludgeoning damage and 6 points of acid damage per round from the pliosaur’s gizzard. A swallowed creature can cut its way out by using a light slashing or piercing weapon to deal 45 points of damage to the gizzard (AC 20). Once the creature exits, muscular action closes the hole; another swallowed opponent must cut its own way out.

A Large pliosaur gizzard can hold 2 Small, 8 Tiny, 32 Diminutive, or 128 Fine opponents.

Worry (Ex): Each round a pliosaur maintains a grapple, it shakes its prey violently, dealing it 2d8+12 damage.

Skills: A pliosaur 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.