A small bird such as a plover or sandpiper, representing the Trochilus described by Herodotus, eats leeches from the gaping open mouth of a Nile crocodile in an early example of Cleaning Symbiosis.
Date 1909
Source http://www.50birds.com/gendalligators2.htm, image taken from Popular Natural History, 1909
Author Henry Scherren
Source: https://commons.wikimedia.org/wiki/File:PloverCrocodileSymbiosis.jpg

The Nile crocodile (Crocodylus niloticus) is an African crocodile widespread throughout Sub-Saharan Africa, occurring mostly in the central, eastern, and southern regions of the continent and lives in different types of aquatic environments such as lakes, rivers and marshlands.