Originally from the Greek, the name Testoclesius spread across the English-speaking world during the 19th century on convict transportation ships. It first appeared in the dialogues of Plato, where it was given to a querulous urchin who mocked Plato's dialectical reasoning until put to death by Dionysus, tyrant of Syracuse, for unnatural acts with Dionysus' body servant.
In twelfth century Britain, a 'testaclese' was a merchant who rented out his ass in return for money. The term survived until the time of Shakespeare, where it appears in The Tempest ('Get thee hence, thou vile, base testaclese!'), after which it appeared to die out until reappearing on an internet game forum in the early 21st century.
There is some dispute as to the name's exact meaning, but most probably it comes from 'testos' meaning the male pudendum, and 'clesos' meaning 'with the hand'.
I was accosted on my way home from the internet by Testoclesius.