The Bark Centipede is a creature native to the Bygors swamp.
When newly hatched, they are harmless insects that feed on the bark of
trees. However, as they mature, they can prove troublesome, as they
begin to hunger for meals that are more alive. They release sweet scents
that tempt creatures to eat them. When ingested, the centipede, however
disfigured, regenerates and consumes the creature from within.

The Queen Bark Centipede is known to take on a disguise of a great tree
which consumes any wildlife that comes into contact with it.
The Queen releases a sweetly scented, thick, sticky resin on it's bark-like skin.
Creatures who are attracted to and trapped by the resin become connected to the
Queen. The process involves a tendril which breaks into the creature's
body and sprouts roots around it's internal organs. The roots slowly
drain all the nutrients, water and energy from the creature, whose body
eventually shrivels and becomes another piece of bark on the Queen's
carapace.
Just before the queen dies, she stands on end, and her body
hardens as she turns into a tree completely. After one year, She
flowers and bears fruits that hatch into more Bark Centipedes, which
feed on the bark of the dead Queen.
The centipede which consumes the heart of the dead Queen is elected as the new Matriarch.

Black undine - Dark faeries of water.
Once cheerful water faeries, they have been contaminated
by blood and turned into Black Undines.

Depressed beings by nature, a black undine appears as nothing but a dark puddle.
They live for hundreds of years, and sometimes wait for decades on end to snatch their prey.
If a creature steps into, or is splashed by a black undine, they are doomed.
The undine's water creeps beneath the skin of the creature and turns it's
blood into water. It then consumes the creature's muscles and internal
organs, and inhabits it's skin. A creature posessed by a black undine is
said to leak thick black liquid from every possible outlet.
Posession is the only way that Black Undines can assimilate a physical form; they
are otherwise restricted to the state of a pool of dark water.
They prize the blood of humans above all, and use their devious minds to ensnare even the wittiest of travellers.