Analysis of A Fantastical Engraving

This freakish ghost has nothing else to wear
But some cheap crown he picked up at a fair
Grotesquely perched atop his bony corpse.
Without a whip or spur he drives his horse
Ghostly as he, hack of apocalypse
To pant and drool like someone in a fit.
This duo makes its charge through endless space,
Trampling the infinite with reckless pace.
The horseman waves a blazing sword around
The nameless crowds he's trampled to the ground,
And like a prince inspecting his domain
He travels to a graveyard's empty plain
Where lie, with pallid sunshine overhead,
From old and modem times, the storied dead.