Trilopod

Trilopods are a race of genetically-engineered alien kaiju that were created and are controlled by the Cryog as a last-resort weapon to exterminate Earth's kaiju so that the Cryog can take over the planet.

Physiology
Trilopods are a hive-minded species. They live and reproduce inside of a giant hive that is pulled through space by the Cryog mothership. There are two variations of Trilopod, large bipedal Beta Trilopods and smaller multi-legged Alpha Trilopods. Whenever a group of Trilopods is battling another kaiju, the Alpha Trilopods will bite the enemy monster and absorb its blood, then crawl onto a Beta Trilopod and fuse with it, mutating it into a clone of the host monster.

History
The Trilopods were genetically engineered by the Cryog in order to wipe out all of Earth's kaiju, allowing the Cryog to take over the planet unopposed. The Cryog emperor Karkaro deployed a pod containing a group of Trilopods to Machu Picchu, Peru, where Godzilla and Megaguirus were battling. The Trilopods defeated Megaguirus and one became a clone of her, then abducted Godzilla and carried him to Los Angeles, where another group of Trilopods was battling SpaceGodzilla. Godzilla and SpaceGodzilla were forced to join forces, and managed to destroy the Trilopods, including one that had transformed into a clone of SpaceGodzilla. Just shortly afterwards, Godzilla collapsed and the Cryog sent the Trilopod hive to Los Angeles. Three Trilopods emerged from the hive and absorbed Godzilla's DNA, becoming clones of him.

Meanwhile, another Trilopod swarm was sent to the Monster Islands, defeating and absorbing most of its inhabitants before taking them away to the hive. Another swarm was sent to Okinawa, where King Caesar had just been awakened. King Caesar easily defeated most of the Trilopods, but allowed himself to be knocked unconscious and taken to the Trilopod hive in Los Angeles so he would be able to help Godzilla destroy the Trilopods once and for all.

Trivia

 * The Trilopods were the first completely original major monster to be introduced in any of IDW's Godzilla comic series.