RIP. I love his work on the earlier Frankenstein films. Turning the Doctor into the real monster and the creatures into his victims was a touch of genius.
Sangster's scripts for the first two Frankenstein films were excellent, especially the amazing gut-punch he delivered to the audience at the end of Revenge of Frankenstein
He should also be given much praise for his work on X: The Unknown
. Who the hell else ever thought of using radioactive mud as a monster?