I think we can safely safe both "He is a cheetah" and "He runs like a cheetah" are metaphoric.

The first more so, since presumably "he" is a human being. But he doesn't run on all fours like a cheetah (or as fast, if we're honest!), so he's only metaphorically running like one.

I think we can safely say both "He is a cheetah" and "He runs like a cheetah" are metaphoric.

The first more so, since presumably "he" is a human being. But he doesn't run on all fours like a cheetah (or as fast, if we're honest!), so he's only metaphorically running like one.

If OP wants to "make" a metaphor, he can use the first form. It will have been said many times before, I'm sure, but I certainly wouldn't call it a cliche.

The second form has probably been used even more often, so if OP only wants to "use" a metaphor, that may be the one to go for.