Beetle, Knell (CR 10)

Large Vermin
Alignment: Always neutral
Initiative: +0; Senses: darkvision 60 ft., scent, Listen +10, and Spot +10

AC: 24 (-1 size, +15 natural), touch 9, flat-footed 24
Hit Dice: 12d8+72 (126 hp)
Fort +14, Ref +6, Will +4
Speed: 50 ft., burrow 10 ft.
Space: 10 ft./10 ft.
Base Attack +9; Grapple +21
Attack: Claw +17 melee
Full Attack: 2 claws +17 melee and bite +14 melee
Damage: Claw 2d8+8, Bite 1d8+4
Special Attacks/Actions: Rend 4d8+12, shake the earth, sonic chime, trample 4d6+12
Abilities: Str 26, Dex 10, Con 23, Int -, Wis 11, Cha 11
Special Qualities: immunity to sonic, sonic healing, vermin traits
Feats: Alertness; Improved Natural Attack (claw); Lightning Reflexes; Multiattack; Weapon Focus (claw)
Skills: Balance +8, Jump +16, Listen +10, and Spot +10
Advancement: -
Climate/Terrain: Underground
Organization: Solitary or colony (3-12)
Treasure: None

Source: Monster Manual III

This ten-legged, beetlelike creature has a hard, shiny red shell. Two wicked claws grope the air before its four beady, black eyes and sharp, jagged mandibles. These mouthparts sit below a massive protrusion that looks like a bell made of chitin, from which you can hear a faint, high-pitched warbling.

Knell beetles are an off-shoot of giant beetles that were long ago warped by overexposure to transmutation magic and sonic energy. Since their original creation, the twelve-limbed vermin have thrived in underground colonies, constructing immense, convoluted tunnel complexes reminiscent of anthills.

A knell beetle's black and red carapace looks like it might conceal wings, but it acts only as durable armor. Two more limbs-jointed, agile, and wickedly hooked claws-jut from each side of a pair of long mandibles. Above the knell beetle's head is a hornlike growth shaped like the bell of a massive trumpet, tapering above the creature's shoulders and flaring out over its sharp jaws. Its four black, insectoid eyes sit in a chitinous brow ridge that runs just below this horn. Essentially, the creature lacks a true head; in its place is the large horn, which warbles and trumpets when the knell beetle communicates to other knell beetles.

Knell beetles, like most vermin, are mindless hunters. They live to breed and expand their warrens, breaking off into new colonies when one has grown too large for an area (typically when a colony has amassed more than fifty members). Knell beetles have also been known to be used as mounts by underdark races. Hobgoblins have domesticated them in the past, as have some orc tribes. These groups know that in great numbers knell beetles only become more effective, and mounted units of knell beetles riders sometimes form the elite fighting units for certain tribes or cities.

A knell beetle usually measures about 9 feet in length and weighs about 1,500 pounds.