Elaphos

Ἔλαφος δ’ ἦν λευκὴ χειροήθης τῷ Σερτωρίῳ καὶ ἄνετος· ἧς ἀφανοῦς γενομένης ὁ Σερτώριος οὐκ αἴσιον ἑαυτῷ τιθέμενος ἐβαρυθύμει τε καὶ ἐπ’ ἀργίας ἦν, καὶ ταῦτ’ ἐπιτωθαζόμενος ἐς τὴν ἔλαφον ὑπὸ τῶν πολεμίων. ὡς δ’ ὤφθη διὰ δρυμῶν δρόμῳ φερομένη, ἀνά τε ἔδραμεν ὁ Σερτώριος καὶ εὐθύς, ὥσπερ αὐτῇ προκαταρχόμενος, ἠκροβολίσατο ἐς τοὺς πολεμίους.
(Appian, Rhōmaïka 13.110)

Sertorius had a white fawn that was tame and allowed to move about freely. When this fawn was not in sight Sertorius considered it a bad omen. He became low-spirited and abstained from fighting; nor did he mind the enemy’s scoffing at him about the fawn. When she made her appearance running through the woods Sertorius would run to meet her, and, as though he were consecrating the first-fruits of a sacrifice to her, he would at once direct a hail of javelins at the enemy. (tr. Horace White)