espanyol
rascador de espalda 
Tool for relieving areas that cannot easily be reached just by one's own hands, typically the back.
1
Now, don't be comparing an Irishman, if you plaze, Adjutant, to a scratch-back Scotchman.
2
But to pay such a price for a scratch-back!-Prodigal
3
As the friends strolled on, naturally enough all the young girls who wished for ribbons, and were possessed of scratch-backs, followed in their wake.