This Hunter variant was created by the mysterious group known only as the "Organization", who were able to develop this particular B.O.W. based on research data stolen by Albert Wesker. In early 1999, Wesker, on orders from the Organization, led an attack on the Umbrella facility of Rockfort Island. His group deployed a number of these creatures following the devastation of the island and Wesker released them to hunt down and kill his former S.T.A.R.S. subordinate Chris Redfield, who was on Rockfort in search of his sister Claire.
The Hunter Kai behaves in virtually the same manner as the Alpha Hunter, but the Organisation were able to devise a more sophisticated means of controlling them. Wesker used a number of robotic surveillance devices called "Spotters" that would scan areas for enemies and then summon Hunters to the area with an alert signal. The Hunter Kais were fitted with a cybernetic eyepiece which would recieve the Spotters' signal, drawing it to the drone's location.