"Ozymandias," probably Percy Bysshe Shelley’s most famous poem, first appeared in The Examiner newspaper of January 11, 1818—a week and a half after the debut of Frankenstein, the first novel by his inamorata and future wife, Mary Godwin. Shelley was in the habit of signing his published works with pseudonyms, and for "Ozymandias," he used the curious name GLIRASTES.

Careful readers of the time might have noticed that Glirastes is not a name borrowed from history or classical literature. But the clues to its meaning didn’t surface for 130 years when in 1948 Carl Pforzheimer bought a cache of previously unpublished Mary Shelley letters, written when she was still Mary Godwin, now in the NYPL Pforzheimer Collection.

In the letters, written in April 1815 to P. B. Shelley’s friend Thomas Jefferson Hogg, Mary Godwin repeatedly and playfully refers to herself as "a dormouse," which the letters make apparent was one of Shelley’s pet names for her. She even signs "Your affectionate Dormouse," and "A Runaway Dormouse" (having eloped with Shelley nine months earlier). In one letter, she’s drawn a tiny sketch of a dormouse.

So what does "the Dormouse" have to do with "Ozymandias"?

As it turns out, Glirastes is a rather silly portmanteau of Shelley’s own design, combining the Greek suffix erastes, meaning "lover of," and the Latin Gliridae, the scientific term for the family of the dormouse. Signing "Ozymandias" with the name Glirastes, lover of dormice, was an inside joke and a show of Shelley’s affection for Mary.

The nickname passed on, in a way, to Mary’s beloved son, William, born in January of 1816, whom the Shelleys called Blue-eyes, and also Willmouse. The only known portrait of William Shelley hangs in the Pforzheimer Collection reading room; it was painted by Amelia Curran in 1819 when Willmouse was three years old, shortly before his death.