The expression “claws of death” can be analyzed through two successive operations:
1. Implicit comparison: conceive of death as resembling a predator in the severity of its grip.
2. Attribution of an attribute: assign to death the claws by which a predator seizes prey.
The first operation makes the second intelligible. Without a mental analogy between death and a seizing predator, attributing claws to death would be an arbitrary statement with no evident rhetorical basis.
But a comparison that remains entirely unexpressed would not produce the poem's full effect. The imagined assertion of claws gives the comparison a perceivable, forceful shape.