The alien would have to have a very different chemistry to ours. And live in a very different environment. Quite radically different.
There are some chemicals that can react with water to release energy. It is just barely possible that such a chemical basis could support an organism. Under the right circumstances, for example, various metals will take the oxygen out of an H2O molecule and release heat.
It would have to be a very different chemistry to ours. And they would need to obtain several other chemicals besides water to sustain themselves.
So to build a little more of an ecology. Imagine a plant that absorbs sunlight and converts something like aluminum oxide and some hydride compound into pure aluminum and water. It might then release the water, possibly as ice crystals if it is cold, and use the aluminum to build its structure. The ice-eater could then come along and use the plant as one part of its food, and the ice as another part.
Conceivably such an organism would be radically susceptible to various chemicals we take for granted. It might spontaneously combust in the presence of free oxygen, for example. (Hmmm... SE's dictionary does not know the word combust. Hmmm...)
Now there is just a huge amount of chemistry that would have to be worked out to make that work. It would involve a lot of things like acids and catalysts and ways to store such things. So, whether it is in fact possible, or even vaguely likely, I certainly can't say.
On the other hand, carbon chemistry also has a huge amount of complicated and subtle reactions that are required for the kind of life we know. If I was required to sit down and work out if carbon-based organic chemistry was possible, given I was only familiar with the conditions in Saturn's rings for example, that would be a daunting task.