This essay brings William Bartram’s 1791 Travels and Thomas De Quincey’s 1849 “The English Mail-Coach” into productive conversation with each other, focusing on crocodilians as a central point of connection. As both physical and semiotic specimens in correspondence networks, crocodilians become a medium of exchange through which Bartram and De Quincey confront the limits of personal identity and imperial expansion. By bringing together these two writers, the essay shows how crocodilians, as a medium of exchange, shift from physical, material specimens to abstract, imaginary symbols, and how natural history’s correspondence networks facilitate an abstraction and effacement of animals.