A private corporation successfully colonizes the planet of Rescha, but discovers too late a race of man-killing deer-oids indigenous to the region. Having killed off every other lifeform native to the planet, they quickly adapt to preying solely on the colonists.
Information on the Kill Deer:
They are fiercely territorial, and engage in death battles to compete for mating rights. Periodically groups of young kill deer will leave the planet to find better, less croweded stomping grounds, how, we don't know....