River Otter
Otters are aquatic weasels. You may find them climbing around on banks, or splashing around in the water, especially around dusk.
-- Wikipedia
Raccoon
Raccoons are not aquatic, but frequently found near water, especially at night, when their eye-shine gives them away.
-- Wikipedia
These are some mammals you are likely to see in and around the water.
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Common Watersnake
This is one of the most common snakes in NJ, inhabiting freshwater streams, ponds, lakes, swamps, marshes, and bogs throughout the state. This snake will likely retreat from you, but if you have to push your luck, this bad-tempered critter can give you a nasty non-venomous bite, and is likely to hold on for quite a while. All snakes are good swimmers, but this one actually likes the water.
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