Kurukuru (Sekai Seifuku)

Little ball-shaped creatures used and possibly invented by Zvezda. They can fuse together into Kaiju (it takes a few thousands of them to form one, though), as individuals they have a form of sentience (to what extent exactly is not known yet) and can also serve as an impromptu inflatable shield (capable of withstanding a few bursts of automatic gun fire), as a hot-air-balloon-like flying device and as a magic satchel (storing a bag bigger than their usual size would normally allow). Natasha can generate them from her tears as an emergency measure, although how that exactly works, wasn't revealed.