A pond slider meeting trouble withdraws into a closed shell. A snapping turtle cannot. Its plastron is reduced to a slim bridge, leaving limbs, tail and much of the neck outside any protection. On land, cornered and slow, it lunges. In water, where it can swim off or bury itself in mud, divers and anglers routinely find the same species unwilling to engage at all.
The bite is real but smaller than legend. Measurements of common snapping turtle bite force fall in the low hundreds of newtons, comparable to a firm human bite, enough to cut a finger badly and nowhere near enough to shear through bone.
The long neck is the reason for care. It reaches back along the shell far enough that gripping the sides of the carapace is unsafe; the shell base near the tail is the recommended hold.