Eagleback

[…] out of the stag's forehead; he gloats over a continent of cheese and a sea of wine; even on eagleback he finds bladders of gin and good roast-beef-fruit; bread-fruit, plum-pudding-fruit […]

[To fly] on eagleback, or in the form of an eagle, is a widespread religious fancy. Aristophanes caricatures it in Peace (1 ff.) by sending his hero up on the back of a dungbeetle.