New Monster: Hammerhead Dungeon Flatworms

"This? No, this was about a year after the dragon." The old woman shifted on her stool, adjusting the peg leg that was rubbing her stump the wrong way. "Certainly one of the least glamorous creatures to ever crawl through the Underdark, but also one of the nastiest." She nodded at the incredulous looks. "Yes, worse than the dragon. Hoarfrost was smart, mean, and powerful. He'd terrorized the Kelban Reach for decades. Finding his lair was a feat in and of itself, especially when you consider the albino kobolds that worshiped him! But the thing about them was that you could basically see from their point of view. There was a brain, and a motivation... The worms? They're just vermin. Almost alien they're so far removed from us."

Pausing to drink from the earthenware mug, one of her audience asked "But if they're just worms, what does it matter what they think?"

"Oh, I suppose it doesn't, really. More that it's impersonal. You're face to face with something that doesn't care, that just views you as food. Plus, unlike Hoarfrost, there was lots of them. And if you don't kill them all? Then they'll just come back."

Hammerhead Dungeon Flatworms (under 8' long)

Armor Class: 8
Hit Dice: 1-3* (S to M)
Move: 90' (30')
Attacks: Slam Bite
Damage: 1d4 (+1/HD)
Number Appearing: 3d10
Save As: F2
Morale: 12
Treasure Type: Nil
Intelligence: 0
Alignment: Neutral
XP Value: 13/25/50

Hammerhead Dungeon Flatworms (over 8' long)

Armor Class: 7
Hit Dice: 4-6* (M to L)
Move: 90' (30')
Attacks: Slam Bite
Damage: 1d8 (+1/HD)
Number Appearing: 3d6
Save As: F5
Morale: 12
Treasure Type: Nil
Intelligence: 0
Alignment: Neutral
XP Value: 125/300/500

In combat, the worms will attempt to knock down their opponent (save vs paralysis on any hit that causes more points of damage than the target has hit dice or be knocked down), and then eat them (free attack on any target knocked prone). They are blind, with an incredible sense of smell. The Hammerhead Dungeon Flatworms are resistant to non-magical weapons (1 point of damage per hit), fire, poison, and 1st and 2nd level spells. Unless completely destroyed, the heads of the worms can regenerate a full body at a rate of 1hp/day.

Ranging in size anywhere from 1' to 15' long, and 6"-12" thick, they're usually about 1/10 as wide as they are long. Their distinctive hammerhead appearance is the result of 2 bone-like growths that the worms use to both dig, and also to bludgeon their prey with. Infested areas usually have a strong sweet & sour smell.

Hammerhead Flatworms are said to be the spawn of the Great Worm, though some claim they're actually just worms that ate of the Great Worm, and absorbed some of its power. Whatever the case, these worms are invasive, aggressive, difficult to kill, and nearly impossible to be completely rid of. When they spread to a new area, the best case scenario is containment and regular eradication. A single surviving worm is able to repopulate any underground space. Worse is that they have no natural predators as they taste terrible.


This post has been inspired by this story.
https://www.livescience.com/62635-hammerhead-flatworms-invade-france.html