Wobblegong

I'm open to other evidence but at the moment the only thing I'm willing to say is special about humans compared to all other animals is the relative lack of cannibalism we've got going on. Everything else– tool use,¹ medicine,² homosexuality,³ murder,⁴ war,⁵ prostitution,⁶ agriculture,⁷ whatever– the animal kingdom will offer you in spades. But eating members of your own genus? We're pretty weird for restricting it to special rituals and extremely rare desperation scenarios! This is probably not unrelated to our giant W at not dying of eating food as often as everything else does. Still, it's unusual.

A non-exhaustive list of examples just off the top of my head:

1. TOOL USE: Primates, corvids, too many smaller genera/species to list.
2. MEDICINE: At least one primate.
3. HOMOSEXUALITY: THE ENTIRE ANIMAL KINGDOM.
4. MURDER: Everything known to be "intelligent" or eusocial pretty much. This includes seabirds, including and especially penguins.
5. WAR: Chimpanzees. Ants.
6. PROSTITUTION: It's seabirds again, including and especially penguins.
7. AGRICULTURE: It's ants again. They're also better at it than us, depending on how you measure things.