Humans may be the self labeled "dominant species" , in the interest of being fair, I shall exclude all primates from this list. It’s safe to say that most people know that primates are intelligent, so I’ll focus on some other creatures. (My favorite ones.)

This list isn't in any specific order.

Elephants: besides being the biggest land animal, they're one of the most intelligent. they pass the mirror test, in which scientists put a mirror in front of them and they examine themselves. Examining yourself in a mirror shows self recognition as a level of self awareness. They can utilize tools, some have been observed using branches and sticks to scratch themselves and as fly swatters.

They can recognize people and different languages we use and our body language. They have empathy and comfort each other with physical contact and vocal sounds. And they mourn their dead, a behavior found in only a few species. They stay stay around their dead for hours at a time.

Crows: Crows show many signs of intelligence, their brains are the size of a human thumb which is large relative to their body. They're on par with primates and can solve complex situations. Crows that live in urban are have adapted to eat several things they see humans eat, and prefer fries in a Mcdonald's bag. While they may not understand what cars are, they use them in different ways. Crows were observed placing walnuts in the street so that passing cars break them open, they even know that cars stop and go due to traffic lights. They can recognize faces, holding grudges against against people, and have a form of gratitude to those who help them. they've been known to give gifts and regularly return to people who feed them. They've also been known to play. They go on top of cars covered in snow and roll down the windshield. Playing shows that they can get bored.

Octopus: Octopi are known to be very intelligent, they play, they can solve complex problems and mazes, and remember solutions. They have large brains, at least to invertebrate standards and have larger and more complex nervous system than other invertebrates. Their ability to mimic other animals such as flounders, lion-fish, and sea snakes and sometimes even objects like a rock shows that octopi can think critically of their situation. Animals usually have one defense mechanism if any to defend themselves, but the mimic octopus not only can change color but makes itself look and act like 15 different species to evade dangerous situations. This shows they think creatively and realize they need different solutions for different problems.

Sometimes they'll take shapes that scientists don't understand.

They are many different intelligent animals on our planet, some people find it humbling to think there are things besides us that are capable of critical thought. Others may have find it unnerving. Thinking of an apocalypse scenario in which intelligent plan to take over and we'd be powerless to stop them. Wherever you may fall on the subject of smart animals, one must agree that it is interesting to think about nonetheless.