- You may be looking for another species by the same name.
Originally, the Kraals were much smaller plants that lived off insects. But by the time the Second Doctor arrived on the scene, they had given to consuming flesh. Every time villagers down below tried to till the land, the Kraals would come down to eat them.
Luckily, the Doctor discovered that the plants' fatal weakness was fire, and men of the village went out to battle with the Kraals, torches in hand. Finally, when the Kraals were forced to the foot of the mountains, the Doctor lit the grass on fire, and destroyed what remained of them.
Though only a small portion of the Kraals were then defeated, the Doctor hoped that news of fire would spread to other villages, and the carnivorous plants would soon be extinct. (COMIC: Freedom by Fire)