@needs native check

can't

Although we say " living things", it sounds strange to talk about "things living" because the first definition of ' thing' is ' object'. Here I would say:
"I can't imagine what entities living on another planet are like."
btw "on another planet" = extraterrestrial
"I can't imagine what extraterrestrial life is like". (only a suggestion since I don't understand the original language)

Firstly I am a native English speaker.

Secondly I believe this is perfectly natural spoken english. If this were intended to be written english I would write it differently.

Thirdly, do people really think that "things" can't be used to refer to living entities? I know the dictionary may not definite it as such but it seems to be common, i.e. "Whats that thing?" in reference to a bug or insect (for example) doesn't sound strange to me.

> I can't imagine what things living on another planet are like.

As it stands, the sentence is ambiguous. It could mean either "I can't imagine what life is like on another planet" or "I can't imagine what the things that live on another planet are like." Sometimes ambiguity is fine, but it seems unlikely that the Chinese has the same ambiguity, so I think whichever one fits the Chinese better is the better choice.

For what it's worth here is the result of Google Translate: "I cannot imagine the creatures on another planet."