A mythological one-eyed race of people inhabiting Scythia, who decorated their hair with gold, and were ever at strife with the Gryphons which guarded the gold mines. If you search for information on them the majority of sites you will find are almost always on the subject of gryphons, will usualy allude to this passage, even with the words 'borrows a simile.'

"Milton borrows a simile from the Griffins, Paradise Lost, Book II.:

'As when a Gryphon through the wilderness,
With winged course, o'er hill and moory dale,
Pursues the Arimaspian who by stealth
Hath from his wakeful custody purloined
His guarded gold.'"

Seriously...you don't even want to know how many times I've even seen the words 'borrows a simile'...