5. Snakehead
Image Source: Brian Gratwicke
These unusual fish are native to Asia, but like so many other flora and fauna, they are beginning to show up in North America and may be making themselves at home in some bodies of water and creating a serious threat to native species. They are extremely aggressive and usually prey on frogs, smaller fish and invertebrates, although they are well-known for attacking anything that moves during mating season. What really makes them unique is their ability to breathe air and survive out of the water for as long as four days. During periods of drought they can burrow into the mud and survive for extended periods. They can grow to about three feet in length which is certainly enough to include among the scariest creatures found in fresh water.
