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/Possessions: None

Source: Monster Manual III

Rend (Ex): if a knell beetle hits with both claw attacks, it latches onto the opponent's body and tears the flesh. This attack automatically does an additional 4d8+12 points of damage.

Shake The Earth (Ex): a knell beetle can channel some of the sonic energy within its body by performing a rhythmic stomping on the ground as a standard action.

Any creature within 5 feet of a knell beetle when it activates this ability must make a DC 24 reflex save or fall prone as the ground lurches and buckles beneath it. Knell beetles are immune to shake the earth generated by themselves or other knell beetles and never need to save against the effect.

If multiple knell beetles activate their shake the earth ability in the same round, the radius of the effect expands as the resonance in the ground combines. For every knell beetle within 5 feet using shake the earth, the radius of the effect expands by another 5 feet. Thus, two knell beetles within 5 feet of one another generate a shaking that affects all creatures within 10 feet of either knell beetle. Three knell beetles within 5 feet using the ability would generate an effect that affects all creatures within 15 feet of any one of the knell beetles.

Creatures with stability or that are considered stable against trip attempts receive a bonus on their reflex save as if they were being tripped (so a dwarf would receive the +4 bonus on the save to resist being knocked prone). The save DC is strength-based.

Sonic Chime (Su): once per day, a knell beetle can emit a cone of sonic energy from the chitinous bell above its head. The cone is 30 feet long, and activating the chime is a standard action. Creatures within the cone take 10d6 points of sonic damage (reflex DC 22 half). A knell beetle is immune to its own sonic chime attack and that of other knell beetles. Knell beetles attacking in numbers use this ability instinctively to heal their fellow knell beetles once several have taken damage (see sonic healing, below). The save DC is constitution-based.

Trample (Ex): reflex half DC 24. The save DC is strength-based.

Sonic Healing (Su): for every 5 points of damage a sonic attack would deal to a knell beetle, the creature instead heals point of damage it has already sustained. If a knell beetle receives more healing than its current hit point maximum, the extra hit points are wasted (the creature does not gain temporary hit points from exposure to sonic damage). A knell beetle gets no saving throw against attacks that deal sonic damage.

Skills: knell beetles have a +8 racial bonus on balance, listen, and spot checks.

Knell beetles in groups fight by using their shake the earth ability, attempting to knock prone as many enemies as possible. They then rush in and trample whatever foes they can before switching to claw, bite, and rend attacks. The creatures only resort to their sonic chime attacks if necessary. Although mindless vermin, knell beetles fight with a certain amount of savage cunning, perhaps also a result of the long ago transmutation experiments that created them.