Quagoo

It burrows into the soft muck of the swamp bed and lies mostly buried, filtering nutrients from the ooze and snapping up small creatures that stray within reach of its wide sticky mouth. Its mud-colored, gelatinous body is nearly invisible against the swamp bottom, and it can loosen and reform itself to squeeze through the tangle of submerged roots. Threatened, it secretes a cloud of murky slime and sinks from view, and a bog that seems entirely empty may in fact be floored with dozing Quagoo, waiting in the mud for the water to still.