In The English Struwwelpeter and the Birth of International Copyright (The Library, journal of the Bibliographical Society, 2013), Jane Brown and Gregory Jones explain that the ancient free city of Frankfurt am Main saw in 1845 the first appearance of Dr Heinrich Hoffmann¹’s Lustige Geschichten und drollige Bilder², a German children’s Christmas picture book. One of the book’s characters, the slovenly boy called Struwwelpeter³, was soon granted eponymous status and his story moved from the back of the book to the front. Der Struwwelpeter, oder Lustige Geschichten und drollige Bilder then began its world-wide career, a remarkable publishing phenomenon that reached Britain in 1848, America in 1849, and continues to the present day. In his cautionary tales, Hoffmann replaced the prevailing worthy but dull content of children’s books with anarchic humour and fantasy, conveyed by startling pictures and pithy rhymes. In ten stories, Struwwelpeter (‘Shock-headed Peter’ in England and ‘Slovenly Peter’ in America) and eleven other wayward protagonists (nine boys, a girl and a huntsman) sprang to life, to delight generations of children and to provide subject matter for generations of literary and psychological interpreters.

¹ Heinrich Hoffmann (1809-94), German physician and psychiatrist
² literally: Funny Stories and Droll Pictures
³ literally: tousle-haired Peter

The following illustration and rhyme are from The English Struwwelpeter; or, Pretty Stories and Funny Pictures (George Routledge & Sons, Limited – 1909 edition):

Shock-headed Peter.

Just look at him! There he stands,
With his nasty hair and hands.
See! his nails are never cut;
They are grim’d as black as soot;
And the sloven, I declare,
Never once has comb’d his hair;
Any thing to me is sweeter
Than to see Shock-headed Peter.

A shock-head is a head covered with a thick crop of hair. In Rob Roy (1817), the Scottish poet and novelist Walter Scott (1771-1832) wrote:

“I will examine Rob Roy before you all, and make you sensible, by your own eyes and ears, of the extreme unfitness of leaving him space for further outrage.” He gave orders accordingly, and the prisoner was brought before him […].
I had never seen this man in the dress of his country, which set in a striking point of view the peculiarities of his form. A shock-head of red hair, which the hat and periwig of the Lowland costume had in a great measure concealed, was seen beneath the Highland bonnet, and verified the epithet of Roy, or Red, by which he was much better known in the Low Country than by any other, and is still, I suppose, best remembered.

In the same novel, Scott also wrote:

As the turnkey held the light in his hand, the beams fell more full on his own scarce less interesting figure. He was a wild shock-headed looking animal, whose profusion of red hair covered and obscured his features.

The adjective shock means having rough thick hair, and, of hair, rough and thick, shaggy. For example, the angora rabbit was described as “the white shock Turky Rabbet” in The Whole Art of Husbandry (1707), by John Mortimer (1656?-1736).

This adjective is a back-formation from shock-dog. The noun shock-dog, or shock, denotes a dog having long shaggy hair, specially a poodle. Epsom-Wells (1673), a comedy by the English poet and playwright Thomas Shadwell (circa 1640-1692), contains the following:

– Lucia: I’ll be condemned to Fools and ill company for ever.
– Carolina: Do not wish that dreadful curse; we [women] are already so much pester’d with gay Fools, that have no more sense than our Shock-dogs; that I long for an acquaintance with witty men as well as thou dost.

In his 1638 comedy The bride, the English playwright Thomas Nabbes (1605-41) wrote:

– Truly sir my neighbour is very skilfull; he cured my little shock of the mange so perfectly, that it hath fam’d him through the neighbourhood for an excellent dog-leech.

The noun shock is a variant of shough, of obscure origin, denoting a kind of lap-dog said to have been originally brought from Iceland. This noun is first recorded in Lenten Stuffe (1599), by the English pamphleteer Thomas Nashe (1567-circa 1601):

(1810 edition)
They are for Ultima Theule, the North-seas, or Island [= Iceland]; and thence yerke over that worthy Pallamede Don Pedro de Linge, and his worshipfull nephew Hugo Habberdine, and a trundle-tail tike or shaugh or two.