The polyphallus or phallus-bird, always rare, are best known from bronze figures in the form of tintinnabula, primarily found in Pompeii. See p. 139 in Grant, Eros in Pompeii, The Erotic Collection of The Museum of Naples and no. 52, p. 69 in Johns, Sex or Symbol? Erotic Images of Greece and Rome. For stone reliefs of the period carved with phalli and apotropaic inscriptions see p. 109 in Grant, op. cit.