From The Art and Popular Culture Encyclopedia
Corydon (from the Greek korudos, "lark") is a stock name for a shepherd in ancient Greek pastoral poems and fables, such as the one in Idyll 4 of the Syracusan poet Theocritus (c.310-250 B.C.E.). The name was also used by the Latin poets Siculus and, more significantly, Virgil. In the second of Virgil's Eclogues, it is used for a shepherd whose love for the boy Alexis is described therein. Virgil's Corydon gives his name to the modern book Corydon.
Corydon is mentioned in Edmund Spenser's The Fairie Queen as a shepherd in Book VI, Canto X. In this section he is portrayed as a coward who fails to come to the aid of Pastorell when she is being pursued by a tiger.
The name is again used for a shepherd boy in an English children's trilogy (Corydon and the Island of Monsters, Corydon and the Fall of Atlantis and Corydon and the Siege of Troy) by Tobias Druitt. 
Other such stock names in poetry include:
- a Rooster = Chaunticleer (from French Chanticler; [chant + clear, in reference to its crow])
- a Fox = Reynard (from French Reignart; reign + -ard, "kingly one")
- a Cat = Felix (from Latin felix, "happy" [influenced by Latin feles, "cat, feline"])
- a Dog = Rufus (from Latin rufus, "red" [influenced by ruff, the bark of a dog])