
So the common snapping turtle is one of three species that makes up the genera Chelydra (the other two species are in Central America and the very northwestern parts of South America). Then when you add in the alligator snapping turtle (genera Machrochelys), you have the two genera that make up the snapping turtle family: Chelydridae.

The specific name for the common snapping turtle is serpentina, which means ‘snake-like’—referring to the turtle’s highly mobile head and neck. While the turtle can be very combative when on land, they actually just want to be to run away—but they don’t want to be followed.

Therefore they try to ‘scare’ off what they’re perceiving as a threat so they can continue on their journey to either another body of water, or if it’s female a place to dig a nest and lay her eggs.
I did not get close enough for it to be ‘frighten’ by me–while it might have made a cool picture seeing it whip it’s neck out and about, it wasn’t worth the danger to either me or the turtle.
There is a high and variable mortality rate for young snapping turtles (pre/post hatching)—since the nest isn’t protected, if it is discovered by predators the eggs can be eaten, and then after hatching the young snapping turtles have to escape notice by predators and make it back to the water. The animals that will go after the eggs include crows, minks, skunks, foxes, and raccoons. After they hatch, the hatchlings can add herons, bitterns, hawks, owls, bullfrogs, large fish, and snakes. Some larger animals will try to prey upon adult snapping turtles—mainly coyotes, black bears, and in the south—alligators and alligator snapping turtles.

They are actually omnivores and will consume both animal and plant materials. While they have a sharp beak, they do usually hunt things that they can actually just swallow—small fish, frogs, small snakes, and invertebrates.
Other tidbits about the snapping turtle:
It takes them somewhere between twelve and fifteen years to reach sexual maturity. So I have no idea how old this particular turtle is, or whether it is male or female.
Turtles in the northern regions that spend ~6 months under ice can get oxygen by gas exchange through the membranes of the mouth and throat—known as extrapulmonary respiration.
They can also generate oxygen through anaerobic pathways, though end up going into oxygen debt by the time the ice melts in the spring.
They have become an somewhat of an ‘invasive species’ in some European and Asian countries. That is because they were first ‘introduced’ as pets–and when people decided that they didn’t want to keep them, they were released into the wild.
They’re listed as ‘special concern’ under the Canadian Species at Risk Act in 2011. While their numbers haven’t dropped to say how the Bald Eagle numbers were in the 1960s, they are being monitored—which since they’re solitary animals and like to hide can be tricky.
I would say that I would like to get a picture of an alligator snapping turtle (I’ve only seen these in the zoo) in the wild—but that would mean possibly crossing paths with one that is on the move, and I’m not sure that is something I really want to accidentally come across on a walk.
References:
https://en.wikipedia.org/wiki/Common_snapping_turtle
http://www.californiaherps.com/turtles/pages/c.serpentina.html