A Klingon admiral who orders the destruction of the Qu'Vat colony to contain the Augment virus.
Krell is a Klingon admiral who oversees the effort to contain the plague created at the Qu'Vat colony, where Klingons tried to use Augment DNA to make enhanced warriors. In Divergence he warns General K'Vagh that if a cure is not found soon the colony will be destroyed to stop the disease spreading.
Krell has also used the Starfleet operative Harris to further his plans. When Enterprise arrives at Qu'Vat, Krell's battlecruiser and two Birds-of-Prey come to wipe out the colony, and Archer has to intervene while Phlox completes the cure.