Not a true hydra, the so-called bog hydra is actually a highly developed archaeomollusc more closely related to krakens and mangrove haunts than to any sort of hydra – despite the primitive and peculiar biology of some hydrae.
Like its cephalopod relatives, the bog hydra’s body is supported by powerful hydraulic muscular action, making it distressingly strong for its small stature; most bog hydrae weigh less than a grown man but can easily uproot small trees and leap great distances. The four highly developed limbs are supported by segments of tough, ribbed cartilaginous mantle jointed to the main mantle plate which protects the torso’s upper surface like a turtle shell. The “toes” are boneless, tough tentacular appendages, as is the prehensile “tail.” The leech-like mouth is capped by a bony beak, below which two antenna pits serve as olfactory sensors.
The creature’s muscular eyestalks are perhaps its most striking feature. Each stalk ends in an eye surrounded by a bony, jagged structure that resembles a mouth and is used for grasping and holding objects and prey. A mass of barbed suckers runs along the bottom of each eyestalk, but these are often concealed beneath flaps of skin when not in use.
The bog hydra is particularly hazardous not just because of its strength, but because it can precisely control the color and texture of its skin membranes to mimic its surroundings, making the creature a deadly ambush predator.