Sh! The Octopus Transformation Scene, 1930

[ER]

Shot in one take, obviously no CGI. A scene that still dazzles today, done with an interesting use of filters that blocked out the shade of the makeup (red, I believe). Impressive and cool.

If you're in a hurry the effect begins at about twenty seconds in and it's worth seeing.

https://www.youtube.com/watch?v=4m3Rea0H_p8

[indianasmith]

Cool scene!

[RCMerchant]

The same effect was used in the 1931 DR.JEKYLL AND MR. HYDE transformation scenes!

[chainsaw midget]

That a nice trick, and one of the better octopus tentacles I've seen in older films.