Looking up the derivation of Zink (by which cornetts are known in Germany) I came across THIS which boggled the mind rather. Being an Acme man myself I'm agog at the prospect of an very expensive fowler-call as used by ...contest callers and hardcore goose hunters alike who appreciate the rare combination of fast reed response and a deep, goosy low end. Nothing to do with geese, or swans, but the Mute Cornett has an integral mouthpiece like certain Monette trumpets favoured by many players today.

Back on thread, the Serpent was adapted by the Goons as The Mukkinese Battle Horn, though I've seen elaborately keyed serpents which don't look too different.