Hivecraft

A flying object resembling a giant stone that suddenly appeared in the year 2028.
It is nearly 1 km long and wide.
In 2028, the Hivecraft moved from the US to the skies of Russia, Asia, the Middle East,
and Europe over the course of 3 days, releasing Storm Ants and Scourgers across the globe, obliterating many countries and regions.
It has continued to traverse the skies ever since. Based on this, the Hivecraft is thought to be the Aggressors‘ mothership, but the facts remain shrouded in mystery.
The giant stone is believed be a sort of Energy Gem mine, with the disc area functioning as a factory producing Giant Creatures and Ravagers.

Mixed in among the Storm Ants are these giant creatures not too dissimilar to a bombardier beetles.
Their gaseous bodies means there is a possibility they would explode when attacked.