Orcas are known to play with seals they've killed and never eat as well. Chimps also participate in clan wars [0]. I'd venture to say that the more intelligent an animal the more capacity they have for needless killing, or at least killing for reasons other than food. What that says about humans specifically I'm not sure, but what I dislike about these conversations is the need to feel like we are so special compared to other animals. We are unique and I'm positive we'll reach a point where we won't need to kill animals for food, but we're not there yet and until then we'll need to be a responsible component of the natural food chain.
[0] https://en.wikipedia.org/wiki/Gombe_Chimpanzee_War