This burrowing, bug-like monster scuttles about on six legs, drooling noxious green ichor from its clacking mandibles.

Ankhegs are an all-too-common plague upon the rural areas of the world. These horse-sized burrowing monsters generally avoid heavily settled areas like cities, but their predilection for livestock and humanoid flesh ensures that they do not keep to the deep wilderness either. Their preferred habitat is rural farmlands, as the loose soil of such regions makes it easy for the creatures to burrow. Tales speak of larger ankhegs that dwell in remote deserts-such creatures likely feed primarily on giant scorpions and camels, and rarely come in contact with civilization due to their remote locations. (A desert ankheg is a Huge advanced ankheg.)

In combat, an ankheg prefers to attack with its bite. Against multiple foes, an ankheg often grabs one of the available targets and then attempts to retreat to safety, burrowing into the ground. A creature carried underground can still breathe with difficulty (the ankheg needs to breathe as well, so its tunnels are relatively porous), but is often eaten alive before its allies can rescue it.

Ankhegs burrow with their legs and mandibles, moving with unsettling speed through loose soil, sand, gravel, and the like-they cannot burrow through solid stone. Burrowing ankhegs can construct tunnels by pausing frequently to shore up the walls with a thicker, less caustic secretion from their mouths. If an ankheg chooses to make a permanent tunnel when burrowing, it moves at half speed. A typical ankheg tunnel is 10 feet tall and wide, roughly circular in cross-section, and from 60 to 150 feet long ([1d10 + 5] × 10). Clusters of ankhegs often share the same territory and create intricate winding networks of tunnels under farmlands, sometimes resulting in sinkholes where too many burrow at once.

Although ankhegs resemble immense vermin, they are in fact much more intelligent than the typical arachnid and, given time and a talented trainer, can even be trained to serve as mounts or beasts of burden. The fact that even "domesticated" ankhegs are prone to squirting acid when frightened or startled makes them unsafe at best in most heavily populated regions, but for more savage races like hobgoblins, troglodytes, and particularly orcs, ankhegs make popular guardians or even pets.

An ankheg resembles an enormous many-legged insect, its long antennae twitching in response to any movement around it. Its legs end in sharp hooks adapted for burrowing and grasping its prey, and its powerful mandibles can snap a small tree in half.

Lurkers in the Earth

The ankheg uses its powerful mandibles to dig winding tunnels deep beneath the ground. When it hunts, an ankheg burrows upward, waiting below the surface until its antennae detect movement from above. Then it bursts from the earth and seizes prey in its mandibles, crushing and grinding while it secretes acidic digestive enzymes. These enzymes help dissolve a victim for easy swallowing, but the ankheg can also squirt acid to take down foes.

Bane of Field and Forest

Although ankhegs receive a certain portion of their nutrients from the soil through which they burrow, they must supplement their diet with fresh meat. Pastures teeming with grazing livestock and forests rife with game are an ankheg's prime hunting grounds. Ankhegs are thus the bane of farmers and rangers everywhere.

Earthen Tunnels

As it burrows through earth, the ankheg leaves a narrow, partially collapsed tunnel in its wake. In these tunnels, one might find the remnants of molted ankheg chitin, hatched ankheg eggs, or the grisly remains of ankheg victims, including coins or other treasures scattered during the creature's attack.

Earthen Tunnels

As it burrows through earth, the ankheg leaves a narrow, partially collapsed tunnel in its wake. In these tunnels, one might find the remnants of molted ankheg chitin, hatched ankheg eggs, or the grisly remains of ankheg victims, including coins or other treasures scattered during the creature's attack.

Oversize insects, ankhegs burrow close to the surface, creating sprawling underground labyrinths. From these tunnels, they burst forth to dissolve and devour smaller creatures using their acid-dripping mandibles and sprays of digestive enzymes.

Ankheg

Burrowing Insectile Predator

Oversize insects, ankhegs burrow close to the surface, creating sprawling underground labyrinths. From these tunnels, they burst forth to dissolve and devour smaller creatures using their acid-dripping mandibles and sprays of digestive enzymes.

Ankhegs are the bane of farmers whose grazing livestock are easy prey for these monsters. Many ankhegs hunt alone, but those in places with ample food might collect in nests of several dozen and threaten whole towns. Ankheg nests can be challenging to wipe out unless the monsters' tunnels are cleared out and their eggs destroyed.

Ankheg tunnels are roughly cylindrical and are often littered with the remains of ankhegs' meals and subterranean treasures. Roll on or choose a result from the Ankheg Tunnel Discoveries table to inspire what might be found in an ankheg's tunnel.

Though they feed on things under the soil, ankhegs prefer live meat—your cattle, your dogs, or you.

Large insect-like monster with a taste for fresh meat that burrows beneath forests and farmlands

The ankheg is a large insect-like monster with a taste for fresh meat, that spends most of its life burrowing beneath the fertile soil of forests and farmlands. An ankheg has six legs, and most of them have brown carapaces, though some are yellow or yellow and brown in various mottled patterns. Adults are up to 10 feet long and weigh about 800 pounds. An ankheg burrows using its legs and mandibles. They usually do not leave usable tunnels behind them, the loose dirt collapsing behind them; however, the can construct a tunnel if they wish, burrowing at half speed to do so. They often dig winding tunnels as a kind of lair, which can be 40 feet below the surface. Groups of ankhegs may occupy the same territory but will not cooperate with each other; the treasure type given should be divided among all the ankhegs in a group. An ankheg usually lays in wait 5 to 10 feet beneath the surface, until it detects the vibrations of approaching prey with its antennae, when it will burrow up to strike.

Large insect-like monster with a taste for fresh meat that burrows beneath forests and farmlands

Ankheg are gigantic burrowing arthropods with chitinous shells. They can subsist on filtered earth, but are not averse to meat. If necessary an ankheg can spit digestive acid with a range of 30-ft. This uses up its stock of acid, which will not be replenished for half a day, and inflicts 4d8 hp damage to a single target (saving throw vs breath weapons for half damage). When feeding, an ankheg dissolves its prey before sucking the juices from the shrunken husk, like a spider. This attack inflicts 1d4 hp damage per round. Ankheg sometimes lurk beneath the earth waiting to feel the vibrations of an approaching creature, thence to attack it by surprise.