Saying that death has claws is not physically true. Nevertheless, the rhetorical purpose is not to misinform the listener about zoology or anatomy. The expression makes death's force intelligible through an image the mind can vividly picture.
Imagination here means the construction of a mental representation, not necessarily an attempt to deceive. The audience knows that death is not an animal and that a state lacks a tongue, yet the images communicate important meanings.
A careful rhetorical analysis should distinguish literal factual truth, figurative communicative purpose, and the assigned senses of individual words.