Cabal

About
The Cabal are one of the many alien races that desperately wants to obliterate humanity. They are very large, possibly hominoid, creatures, standing at least two times taller than the average man.

Gameplay
The Cabal seem to employ, at least occasionally, shields as well as bladed firearms. They appear to use their shields as very powerful melee weapons similar to the Hunters in the Halo series.

Speculation
It is possible that the Cabal are also more informally known as the War Rhinos, although the War Rhinos could be an entirely seperate species.