Sparkeaters

Sparkeaters are horrifying creatures only found on Seibertron. Not much is known about them or their origins but the mere thought of them is enough to turn away some of the toughest warriors.

They are rare to the point of essentially being "cryptids" and are often considered an "old tale made up to scare children", this is largely due to their rarity and the fact no one has survived an encounter with them.

Biology
Sparkeaters are large gangly creatures with pale pasty flesh.

They appear thin and decrepit but this is largely due to how the skin they do have hangs from their bodies.

They have protruding bones along their arms, chest and back, thick veins are visible beneath their skin and a row of spines along their abdomen. No eyes are visible on their beaked heads and their brains are always exposed.

Their feet resemble that of an Earthly creature called an "ostrich" and their hands display a similar property to that of a gecko's allowing them phenomenal climbing abilities.

A secondary set of arms tipped with sharp claws allow them to tear through obstacles to get to prey, this combined with their great running speed makes them near impossible to escape.

They are known for using their beak to crack open a Seibertronians chest plates before using it and it's venomous fangs to tear chunks of flesh and bone out in order to get to their prized meal - The Spark.

The nickname Deathwailers come from their inability to make true noises, their tongue and rancid vocal chords are unable to produce anything but a strained, breathy wail.

The most curious thing about them, however, is that their exposed brain has inorganic/metal nodes embedded into it, raising further questions about their origin.

Trivia

 * Tfwiki page on Sparkeaters.
 * The sounds it can make are similar to this, however, imagine that but more horrifying as if mixed with the screaming wails of a dying animal.
 * Sparkeaters have a 100% fatality rate upon being encountered by Seibertronians, probably adding to the lack of knowledge about it, if they don't eat you, their venom will get you.
 * They are sometimes depicted with black drool in artworks despite the real beast having clear saliva.
 * When designing it I took some influence from Dead Space.