There are some great similes and metaphors kicking about in literature but the one thing that always bugged me was the use of them when the example you give may not exist in the time period or universe. What i mean is could you say take the example "Thrown around like a rag doll" (cliche I know but not going to think to hard about example all i be here all day staring at screen) when describing something in the scene that was say set in the stone age. The "Rag doll" doesn't exist yet, but the reader knows what it is. Granted in first person it is clearer that it best not to use but Omnipresent and other 3rd person views is where i get confused. In a space fantasy set on a far away planet you could describe a creature as mouse like, but what there are no mice (so tempted to write mouses) on that planet and the characters have never been in contact with one?