It can encyst. That is, secrete and form a sort of protective envelope.
6 seconds sound clip from the The Angry Red Planet movie soundboard.
You can hear this line at 01:05:57 in the Blu-ray version of the movie.
Quote context
[...]
- It'll take time, but it probably can eat right through the ship.
- Well, we've got to get rid of it some way.
- But how? It can't even be touched with anything we have.
- You've experimented with amoeba on Earth. What sort of thing affects them?
- They're almost impossible to kill. Even if you cut them in half, both parts will live.
- Now, there's got to be some way to get at it.
- It can encyst. That is, secrete and form a sort of protective envelope.
- That's how it withstood the sonic gun.
- Heat, fire... I could turn on the rocket.
- You can't do that. With that creature clogging our thrust chamber, we'd have an internal explosion.
- Well, we've got to do something!
[...]