Pratchett says Mort would have thought she [Ysabell] looked Pre-Raphaelite when he first encountered her, if he had only ever heard the word.- Cockroach (Wikipedia)
Cockroaches (or roaches) are insects belonging to the order Blattodea (Blattaria). About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known pests.