(Not my photo, just random interwebs share.)
I don't know if snails have enough brain cells to be actually terrified. (Science must answer this.)
Apparently sulcata tortoise hatchlings are quite fast because they're, you know, small.
But most turtle species are actually quite speedy compared to snails. In fact, some herbivorous turtle species eat snails for protein! Just to assert that they're the speediest of all. *chomp*
Both painted turtles and snappers can move faster than a human can sprint in a short spurt, if they want to.. Idk about alligator snappers just the regular ones in the north anyway.