Night of the Lepus (1972)
Night of the Lepus is a science fiction horror thriller featuring an Arizona rancher Cole Hillman, dealing with massive rabbit overpopulation on his land, he calls on a local college president, Elgin Clark, to help him. In order to humanely resolve the matter, Elgin brings in researchers Roy and Gerry Bennett, who inject the rabbits with chemicals. However, they fail to anticipate the consequences of their actions. A breed of giant mutant rabbits emerges and starts killing every human in sight.