He has a funny habit of shedding his cells and replacing them with polarized silicon, which gives him a prolonged resistance to adverse environmental conditions.
14 seconds sound clip from the Alien (1979) movie soundboard.
You can hear this line at 00:43:51 in the Blu-ray version of the movie.
Quote context
[...]
- Well... Well, as I said, I'm still... collating, actually, but, uh,
- I have confirmed that he's got an outer layer of protein polysaccharides.
- That's plenty. What does it mean?
- Please don't do that. Thank you.
- Well, it's an interesting combination of elements, making him a tough little son of a bitch.
[...]