Piranha

Most people know not to mess with piranhas. They are deadly little creatures that usually attack in groups. Although adult piranhas still aren't very large, they do have very sharp teeth. However, their teeth aren't very large either, so when a piranha attacks, it is rarely a killing blow. Instead, when attacking, piranhas eat their prey alive by tearing off its flesh.

http://www.extremescience.com/zoom/index.php/animal-kingdom-records/100-piranha

Even as babies, piranhas are still killers. When first born, a piranha will eat small crustaceans or any other small animals that get too close. Baby piranhas will also eat fruits and aquatic plants. Even though piranhas are born with sharp teeth and ferocity, they are not safe. Adult piranhas have been known to eat their own babies and other piranhas will certainly sink their teeth into baby piranhas, if they get the chance.

http://animals.howstuffworks.com/fish/piranha-eat-cows.htm

Adult piranhas, which travel and hunt in groups, will eat just about whatever they can catch. Their diet includes other fish, animals that get too close to the water, and even sometimes people.

http://www.gurlygoround.com/setting-up-a-piranha-tank

In my opinion, piranhas aren't really that amazing. At first, I thought they would be a perfect topic to write about because I haven't talked about any fish yet. It was cool reading about how piranhas eat their prey alive, but, like birds, I've never really been interested in fish. Piranhas just seem like tiny sharks that can't get their mouth around their food. I really don't know what a piranha looks like a cross between. If I had to guess, I would say that the piranha looks like a mix between a shark, a trout, and a barricuda and the result having swallowed a ping pong paddle.