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More fun with Fantastical Mounts with the Thornback Crawler

Among the twisted jungle vines and rotting ruins, there is the sound of a thousand legs clicking in unison. Not all predators slither or stalk—some skitter, and those are often the deadliest.

The Thornback Crawler is one of the strangest and most unnerving creatures to ever serve as a mount. Native to dense, humid jungles and forgotten temples reclaimed by nature, these massive centipede-scorpion hybrids are surprisingly intelligent, fiercely territorial, and able to scale nearly any surface—sideways or even upside-down.

Though they were once feared as living traps of ancient tombs, some cultures have learned to tame them from birth, using them as war-beasts, siege climbers, and jungle mounts capable of silent traversal over otherwise impassable terrain.

Nerdarchy has a product called Fantastical Mounts over on the store in the a similar format to below. So now you have more options for your world with another crazy mount ideas. You can see the Gloomtail Drifter here.

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Thorns and Shadows

Thornback Crawlers range from 10 to 15 feet in length when mature, with long segmented bodies covered in barbed ridges that shed and regrow like scales. Their armored exoskeletons shift in hue, mimicking the shadows and foliage of their surroundings. Their eight pairs of clawed legs grasp with unnatural strength, allowing them to cling to sheer stone or swing from tree to tree like living bridges.

The creature’s tail ends in a hardened scythe-like barb, while their midsections can fire a small burst of venomous quills when startled or threatened.

Despite their monstrous appearance, thornbacks are surprisingly quiet. In fact, many jungle stalkers claim that if you can hear a crawler coming, you’re already dead.

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Tomb-Born Beasts

Many believe the thornback was engineered—or perhaps corrupted—by the same ancient spellcraft that animated temple guardians and jungle horrors. Some ruins contain murals depicting thornbacks alongside robed figures, as beasts of burden or living traps.

Those who have raised thornbacks from hatchlings claim they are smart enough to recognize faces, hold grudges, and even mimic simple body language. They bond with only a single rider, and reject others with hissing, venomous contempt.

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Trade Goods and Usage

The thornback’s ridged spines exude a toxic resin, which when carefully harvested can be refined into venom-coated arrows, hallucinogenic salves, or even poisons that cling to metal and stone for weeks. A trained alchemist can fetch 30 gp per vial of thornback resin on the open market.

The creature’s natural camouflage also makes it a prized pet for elite assassins, beast hunters, and ruin-delvers who value silence and climb-speed over speed and brute strength.

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Thornback Crawler

Large monstrosity, unaligned

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Armor Class 16 (natural armor)
Hit Points 58 (9d10 + 9)
Speed 40 ft., climb 40 ft.

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STR 17 (+3)
DEX 16 (+3)
CON 13 (+1)
INT 4 (–3)
WIS 12 (+1)
CHA 5 (–3)

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Skills Stealth +7, Perception +3
Damage Resistances poison
Senses darkvision 60 ft., tremorsense 30 ft., passive Perception 13
Languages —
Challenge 3 (700 XP)

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Traits

Wallcrawler. The crawler can move along vertical surfaces and ceilings without needing to make an ability check.

Chameleon Carapace. When not in bright light, the thornback has advantage on Dexterity (Stealth) checks made to hide.

Venomous Quills (Recharge 5–6). The thornback releases a burst of barbed quills in a 15-foot cone. Each creature in the area must succeed on a DC 13 Constitution saving throw or take 9 (2d8) poison damage and be restrained for 1 minute. A creature restrained this way may repeat the saving throw at the end of each of its turns, ending the effect on a success.

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Actions

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target.
Hit: 10 (2d6 + 3) piercing damage and 4 (1d8) poison damage.

Tail Slash. Melee Weapon Attack: +5 to hit, reach 10 ft., one target.
Hit: 11 (2d8 + 2) slashing damage.

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Steps to Training a Thornback Crawler

Thornbacks cannot be broken—they must be bonded. The key to bonding is mutual patience and blood familiarity. Most who ride them either raised them from an egg or were accepted after a dramatic show of respect (often involving a painful but survived venom strike).

These creatures do not forget betrayal and refuse to be ridden without completing all five steps in order. If a rider ever strikes their crawler in anger, the bond is broken—possibly forever.

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Cost and Gear

• Cost (trained): 1,000 gp

• Availability: Uncommon; usually traded in secret jungle markets or raised by ruin cults.

• Custom Gear: Requires a segmented harness with padded plates and claw anchors. These are rare and cost 300 gp or more depending on material.

Thanks for reading. Until Next Time, Stay Nerdy!!