Bombshell

Noun

 * 1) a bomb or artillery shell designed to explode on impact
 * 2) something that is very surprising, shocking, amazing or sensational
 * 3)  someone who is very attractive (compare sex symbol)
 * Diana Dors, the "1950s blonde bombshell" ...

Thesaurus
aerial bomb, antipersonnel bomb, astonishment, blockbuster, blow, bomb, carcass, catch, concussion grenade, depth bomb, depth charge, earthshaker, eye-opener, fire bomb, gas grenade, grenade, hand grenade, incendiary bomb, incendiary grenade, infernal machine, joker, kicker, peripeteia, petard, revelation, shock, shocker, staggerer, startler, surprisal, surprise, surprise ending, surprise package, surprise party, switch, tear-gas grenade, thunderbolt, thunderclap, time bomb, wall grenade