Unlike the dragons of other worlds, the dragons of this one are eyeless (relying on echolocation and smell), lack front legs, and have finned tails. They are roughly the size of battle tanks or battleships, and they fly with slow manta-ray like speeds (though they can accelerate for quick dashes if need be). Despite being covered in seemingly-thick plates of blue and violet scales, they are not impervious to bullets or missiles, and generally strike from altitude.
They achieve these air-to-surface attacks with an unusual breath weapon: laser beams. These high-energy blasts are both super-heated and electrocuting plasma as well as powerfully concussive. A battleship or city block can be destroyed with only a few hits from such a laser; a flight of such dragons can thus easily level whole cities. This planet, thus, is ruined and conquered.
The dragons of this world are different from those of other worlds in another way: they were made by an extraterrestrial intelligence to be living mind-controlled siege engines. Themselves highly varied in physical structure, they have conquered multiple planets through the exploitation of genetic engineering to create macroscopic biological weapons. Each individual somehow contributes to the species-wide goal of planetary consumption and proliferation.
Expediting this interplanetary conquest are organic technology of various types. Even their buildings are grown, with walls of ribbed chitin and biochemical energy generators and batteries. While organic technology has several draw-backs, they make extensive use of preemptive vaccination and at-will low-consumption hibernation states. Apparently their goals are to invade worlds from sleeper ships, eliminate sentient competition through sudden overwhelming force, consume all organic resources, and then move on to the next planet to reproduce the cycle.
(I do not own the images in the above collage, and all copyrights belong to their respective owners.)
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