He also claims a place in the Latin literary tradition by echoing well-known and respected writers. It is to be noticed, however, that where Phaedrus and the slightly earlier poet Horace adapted the same fable to satirical themes, they often used different versions of it. In Horace a crow ("cornicula") is the subject of The Bird in Borrowed Feathers; in Phaedrus it is a jackdaw ("graculus"). In the case of The Horse that Lost its Liberty, Phaedrus has it disputing with a boar and Horace with a stag. Neither do they agree in their account of The Frog and the Ox. Horace follows the story found in Greek sources; the frog’s motivation is different in Phaedrus, and it is his version that Martial follows later. Moreover, in following the model of Aesop, the enfranchised slave, Phaedrus' satire is sharper and restores “the ancient function of the fable as a popular expression against the dominant classes”. Another commentator points out that “the Aesopian fable has been a political creature from its earliest origins, and Phaedrus, (who was La Fontaine’s model), though more openly subversive, has claims to be the first proletarian satiric poet”.