Converting prehistoric creatures

[Cleon]

Added to Homebrews.

Since they were clearly aquatic, added that subtype. Do you want any ability to survive on land?

Funny, I was sure I had Aquatic in my last draft. I though I copy-and-pasted the Types of the Marrella.

As for surviving on land, I think this one will stick to the water.

Upon reflection, I'm wondering whether we should cut out the Climb speed and leave it as a swimmer & crawler...

...no, if it's got a mollusc-style foot it would be a good climber, since it can use it to grip vertical surfaces.

An odontogriphus is 18 feet long and weighs x pounds.

Tricky. Its body plan doesn't match well to anything living so we don't have anything to compare it to.

Still, it's a free swimmer so must have the same density as water. It's roughly 18' long and 6' wide. If we knew its thickness we can calculate its mass. Unfortunately, there's no way to tell from the fossil.

It's compared to a flatworm, which have bodies about one twentieth as thick as their length (or about 30-50% as thick as their width).

That suggests an average thickness of about 9 inches to a foot, which gives a volume of ... 75-100 cubic feet, or 4,700 to 6,250 pounds weight.

Call it 5000 pounds.

That's over the standard weights for a Large creature, but there are Oozes and other living things that are overweight for their Size.

Incidentally, that's about the weight of a big (~25' ft.) manta ray, a creature their swimming style is compared to.

"A typical odontogriphus is about 18 feet long and weighs up to 5,000 pounds, most of its 6 foot wide body is less than a foot thick."

 

[Shade]

Updated. Finished already?

 

[freyar]

Guess so!

 

[Cleon]

Updated. Finished already?

I'd remove the mention of "warm-blooded prey" from the flavour text. It seems an unnecessary carry-over from the Leech. They probably mostly feed on fish and giant arthropods, after all.

Also, the original description says "its attack method is obvious: drop down on the prey from above, bite in, and start sucking". Shouldn't we mention the "death from above" in tactics?

Further, it says "dropping itself down on man-sized or smaller prey" which implies they only attack creatures smaller than themselves (which makes sense following the standard Improved Grab / Constrict rules. I think we should add that in too.

Revising...

Odontogriphus is a prehistoric marine bilaterian. It spends most of its time swimming across the sea floor, hunting for prey from which to obtain nourishing blood.

A typical odontogriphus is about 18 feet long and weighs up to 5,000 pounds, most of its 6 foot wide body is less than a foot thick.

COMBAT

An odontogriphus hunts by dropping on prey from above, grabbing hold with its mouth, and then sucking its victim's blood while squeezing with its powerful bodies. They only attack creatures smaller than themselves.

 

[Shade]

Updated.

 

[Cleon]

Updated.

Looks finished.

 

[Shade]

Leanchoilia
FREQUENCY: Uncommon
NO. APPEARING: 1-4
ARMOR CLASS: 2
MOVEMENT: 4 (crawling and swimming)
HIT DICE: 5
THAC0: 15
NO. OF ATTACKS: 3
DAMAGE/ATTACK: 1d4/1d6 (x2)
SPECIAL ATTACKS: Entangle
SPECIAL DEFENSES: Nil
SIZE: L (8’ long)
MORALE: Average (8)
XP VALUE: 270

This arthropod has fin-feet of the sort common to Burgess creatures such as Opabinia and Yohoia, enabling it to both swim and crawl at the same slow, steady pace. It is otherwise noted for three things: a pair of antennaelike frontal appendages, each ending with three whips; an armored shell (in the BUGHUNTERS game, this blocks four points of damage per attack and reduces lethality ratings by two); and a saw-edged tail spine that may have been used for digging. (It is not a weapon, but you don’t need to tell the players that!)

In battle, Leanchoilia lashes out with its whiplike arms, doing 1d6 points of damage with each. Aside from laceration damage, they also may entangle a target of mansize or smaller, making him unable to fight back or escape unless he makes a Strength roll on 1d20. Prey that has been successfully snagged will be dragged to the mouth, which inflicts 1d4 points of biting damage per combat sequence. As the creature can come out on dry land for an hour or so, it is a considerable threat to human life.

Originally appeared in Dragon Magazine #204 (1994).

 

[Cleon]

Leanchoilia

How about modifying the Marrella - reduce the Str and Con by "half a size", give it three whips as a primary attack (with Improved Grab), plus a secondary bite attack (which it can use to Gnaw a grabbed victim).

Hold on! Looking at the Marrella why in the Cambrian Ocean does it have Charisma 9? Shouldn't it be Cha 2 or 3?

Anyhow, something like this for the new one:

Leanchoilia
Large Vermin (Aquatic)
Hit Dice: 5d8+10 (32 hp)
Initiative: +0
Speed: 10 ft. (2 squares), swim 10 ft.
Armor Class: 18 (-1 size, +9 natural), touch 9, flat-footed 18
Base Attack/Grapple: +3/+11
Attack: Whip +6 melee (1d6+4)
Full Attack: 3 whips +6 melee (1d6+4) and bite +1 melee (1d4+2)
Space/Reach: 10 ft./5 ft. (10 ft. with whip)
Special Attacks: Gnaw, improved grab
Special Qualities: Darkvision 60 ft., vermin traits, water dependency
Saves: Fort +6, Ref +1, Will +1
Abilities: Str 19, Dex 10, Con 15, Int —, Wis 10, Cha 2
Skills: —
Feats: —
Environment: Any aquatic
Organization: Solitary or cluster (2-4)
Challenge Rating: 2?
Treasure: None
Alignment: Always neutral
Advancement: 6-10 HD (Large); 11-15 HD (Huge)
Level Adjustment: —

 

[Shade]

That seems about right. I'll lower the Cha on the marrella as well.

 

[freyar]

Seems pretty good to me too.