The night before the demo presentation, I created a good pterodactyl scream by taking a recording of dolphins, reversing it, and dropping the frequency. Sounds strange, but I didn't have much time, and the effect was surprisingly good. A woman from marketing was trying the ride and raved that we got the pterodactyl scream just right.
Think about what good foley means to you. The arrival or departure of the TARDIS. Godzilla's roar. The sweepy red light on KITT. The "pew pew" of a laser gun that shouldn't really make any noise at all. The incongruous farty buzzing sound of a GAU-8 taking apart a tank. The crackle and hum of a light saber in motion. The "errr aka-chicka aka-chicka tullet-peppa tullet-peppa" of Ripley entering the Nostromo's computer core. The signature sound of a modem handshake. The ringtone of the very first mobile phone you ever owned.
It's just as important as the visual portion of a story, but gets much less respect.
Perhaps Toho would have added it if the recording & reproduction systems of the time could have produced it, I don't know.
Wikipedia says it was created via "...rubbing a resin coated glove along the string of a contrabass and then slowing down the playback" http://en.wikipedia.org/wiki/Godzilla
shrugs
