"B" is for "Benthak"

Benthak

No. Enc.:  0 (1d8)
Alignment:  Neutral
Movement:  45' (15')
  —Swim:  75' (25')
Armor Class:  2
Hit Dice:  8
Attacks:  3 (2 claws, 1 bite)
Damage:  2d8 / 2d8 / 1d8
Save:  L4
Morale:  11
Hoard Class:  None
XP:  1,060

Benthaks are chitinous, multi-legged, ill-tempered crustaceans the size of Ancient rhinoceroses.  They prowl the floors of the deepest oceans, devouring anything they encounter.

Benthaks employ their claws with blinding speed, stabbing and smashing their prey to pieces.  And said claws secrete a chemical that disrupts metal at the atomic level, providing +2 To Hit and Damage against submersible vehicles, robots, and targets encased in metallic armor.

There are tales of great Ancient undersea bases being overrun with benthaks.  The beasts sheared their way through steel and duralloy once thought impregnable to get at the occupants inside...whose horrifying final fates involved swirling vortices of crushing waters, snapping jaws, and gore.

Mutations:  Toxic Weapon ("Subatomic Claws")