FWIW - The octopus in "It Came From Beneath the Sea" actually had SIX tentacles.
You're right - my mistake.
I think my misinformation came from (very) old articles on Harryhausen published in Famous Monsters of Filmland magazine.
According to Harryhausen himself, in his book Film Fantasy Scrapbook:
"For those of you that have seen the picture, you may or may not have noticed that the octopus only had six tentacles. By necessity, we had to work on a rather tight budget... I sometimes wonder if the budget had been cut anymore if we might not have ended up with an undulating tripod for the star villain of the picture."
Signor V.
"For me, there's only my wife..."
"Sure I cook with wine - sometimes I even add it to the food!"
"When life itself seems lunatic, who knows where madness lies?"
"It was a grass harp... And we listened."
"Do any human beings ever realize life while they live it? Every, every minute?"
