Yay for J.!
B.'s husband J., the biology major, identified my nasty bug as a Dobsonfly. According to this site, the male's mandibles can't hurt you, but the females can. So those nasty-looking pincers won't kill me. I think.
They're attracted to bright lights at night and it just so happens that I turned our dusk-to-dawn light, which is above that window, on last night. That will be turned off right away!