A photographer named Igor Altuna was watching a leopard kill a vervet monkey. It was a mother and had a young baby monkey still clinging to her, unaware his mother was now dead… the leopard carried both the carcass and the attached infant to her own baby.
The cheetah placed the dead monkey down. Before the eyes of the baby monkey, mother and child leopard consumed the dead creature. And then, the young leopard cub toyed around with the baby monkey who by now was well aware of the fact his mother was dead and gone, seeing as though the predators just ate her flesh in front of him. For over an hour, the big cats played a cruel game with the little monkey, the mother using it as “hunting practice” for the cub… then, they finally killed the tiny creature to put it out of it’s misery…
I’m not sure if I would call nature cruel, necessarily. It is cold and detached, if anything. Murder, torture, even psychological torture, is inflicted freely and generously without a care in the world — the weak get eaten, and they suffer. The strong eat, and cause suffering. There is no compassion for any creature not of your species, tribe or family.