The K-Bora are a group of four natives on Heiligdom, and the main antagonists that appeared in S08Ep4: Heiligdom.
History
The four Nanjarie were numerously encountered by The Diamond Authority prior to the series, seemingly always able to win up over them throughout each encounter.
Season 8
The K-Bora make a return when the Diamond Authority visit Heiligdom, them being responsible for capturing Yellow Diamond and planning to eat her. Much of the visitors (excluding White Diamond) arrived and confronted them, only for them to easily drive them away. They were confronted by White Diamond later on though, and while it is unclear as to their current state, it is clear their home was destroyed afterwards.
Abilities
Elasticity
The four Nanjarie apart of the K-Bora are shown to be able to defy reality, and able to morph their own bodies in any way they so chose to. According to Peridot, natural Nanjarie are incapable of doing this, hinting that only the K-Bora strictly are capable of this trait.