Predators are animals that eat other animals.
Nearly every animal on earth that is classified as "cool" is a predator. While some people admire the strength of horses bulls and elephants, ultimately the biggest bad-asses in the animal kingdom are the creatures that kill and eat horses bulls and elephants. (although few have the ball/brains ratio necessary for attacking elephants).
If you can kill and elephant from a mile away, no, you don't have balls.
These are the animals most of us think of when we hear the word "predator". They are all badass, and are born with murder weapons attached to their head and hands. Some are awesome and impressive, while others are just downright terrifying that Nature would be such a bitch to invent them.
Lions, tigers, leopards, jaguars, mountain lions... Even if you hate cats, you have to respect these things. Most are solitary, preferring to keep their kills for themselves, because sharing is for pussies (no pun intended. Even ironic ones). Big cats are typically viewed with a mix of respect and fear by natives, and with good reason. They are so powerful, that even when they are trying to be helpful, they can still fuck you up.
Just ask Roy.
Tigers are the biggest, followed by lions. Despite what Disney and many other movies would have you believe, tigers are native to Asia and never make it to Africa (they spend too much time eating people in India and trying to avoid getting killed for their dicks in China). Lions are native to Africa, but aren't the Kings of the Jungle; they don't even live in the jungle. That's like calling penguins kings of the forest. It's just stupid.
Mix lions and tigers and you get ligers, which are awesome because they don't stop growing their entire life. Get us a liger (paint it green, of course) and our own Castle Greyskull and we can hold off Skeletor.
Next you have leopard and mountain lions. They aren't as big as the lions and tigers, but they are some of the most successful predators on Earth. They manage this by being smart, fast, good climbers, and bright enough to only occasionally attack hippies in California.
Big cats also have the Cheeta, which is the world's fastest land animal.
Dogs are man's best friends, unless they are starving or from the wild, in which case they become man's best, picking man's out of their teeth, because they ate him. (Shut up)
For all the loyalty and happiness we get from dogs, there is a little part of our brains that remembers that the cute furry beast we put our trust in is descended from a deadly predator that is still central to a lot of the "scaring the ever loving piss out of us" that we do as a hobby. For example, mankind has probably be interacting with goats almost as long as we have with dogs, but we don't have weregoats or movies about rabid goats trapping us in a car for two days.
This is why you give your dog a dignified name.
This is why even little wuss breeds like dachshunds and chihuahuas are in reality little badasses. Because they are tiny rat sized wolves. They remember deep in their tiny DNA what it was like to take down moose; and you don't have antlers.
Wolves aren't the only dogs in the world looking to make us their next meal, if only because when we don't have a firearm, we are pretty harmless. There are also coyotes, African wild dogs, and dingoes. Really, the only continent that does have some species of dog that could and probably would make you a snack is Antarctica, but they have seals that will kill you, so it balances out.