Cats: torture their prey to death as a form of play.
“Play” isn’t just an idle pursuit. It’s also a form of safe practice of one’s life pursuit. In the case of cats, they evolved to be almost 100% carnivores, so it’s natural for them to live, breath, and yes practice / play at honing their pursuit and kill skills. It is literally their fundamental job that separates them from dying off.
Dolphins: you dont want to know.
Let’s not forget two things here: 1) much of the rapey stuff (as with ducks) also serves the fundamental life model of reproduction being one of the highest natural priorities, however its accomplished; 2) dolphins are hella smart, just like us, and if anything, it goes to show that smart species with idle time can devise some pretty wild pastimes.
If a person did half the stuff animals do, no one could look at them the same again.
To compare the lifestyles of a single animal species (humans) with all the others is a fool’s mission. In fact, most animals live fairly predictable, innocuous lives. They have their classic interactions with the world and don’t tend to bother other species-- mainly because it’s not worth their time.
People do some awful things but we are also probably the only species that has members that sympathise with other species above ourselves.
Nonsense. Pretty much all higher social / tribal animals can pretty easily sympathise / empathise with other species, such as our fellow apes, dogs, cetaceans, corvids, elephants, parrots, and even domestic cats.