But the serpent with his sharp unsleeping eyes had seen them coming and now confronted them, stretching out his long neck and hissing terribly. - Apollonius of Rhodes

Ἀρχόμενος σέο Φοῖβε παλαιγενέων κλέα φωτῶν
μνήσομαι οἳ Πόντοιο κατὰ στόμα καὶ διὰ πέτρας
Κυανέας βασιλῆος ἐφημοσύνῃ Πελίαο
χρύσειον μετὰ κῶας ἐύζυγον ἤλασαν Ἀργώ.

At one moment both of them were staring at the ground in deep embarrassment; at the next they were smiling and glancing at each other with the love-light in their eyes.

And now, from somewhere in the bowels of the earth, from the smoky stronghold where they slept, the pair of bulls appeared, breathing flames of fire. The Argonauts were terrified at the sight. But Jason planting his feet apart stood to receive them... He held his shield in front of him, and the two bulls, bellowing loudly, charged and butted it with their strong horns...