Diogenes Laerius, Lives of the Philosophers 5.6 [Heraclides 89-90]
“He seems to have freed his country from tyranny by killing the monarch, as Demetrius of Magnesia claims in his People with the Same Names. Demetrius also tells this next story about him.
From the time he was a child he raised a pet snake. When he was near death he told one of the people he trusted to hide his body but to put the snake on his funeral litter so that he might seem to have transitioned to a place among the gods.
They did this, but while the people were taking Heracleides in his procession and were shouting out, the snake heard it and came out of the shroud, troubling people. Once everything was uncovered, Heracleides was known as he truly was, not as he seemed to be.”
Δοκεῖ δὲ καὶ τὴν πατρίδα τυραννουμένην ἐλευθερῶσαι, τὸν μόναρχον κτείνας, ὥς φησι Δημήτριος ὁ Μάγνης ἐν Ὁμωνύμοις. ὃς καὶ τοιόνδε ἱστορεῖ περὶ αὐτοῦ· “θρέψαι αὐτὸν δράκοντα ἐκ νέου καὶ αὐξηθέντα, ἐπειδὴ τελευτᾶν ἔμελλε, κελεῦσαί τινι τῶν πιστῶν αὑτοῦ τὸ σῶμα κατακρύψαι, τὸν δὲ δράκοντα ἐπὶ τῆς κλίνης θεῖναι, ἵνα δόξειεν εἰς θεοὺς μεταβεβηκέναι. ἐγένετο δὲ πάντα. καὶ μεταξὺ παραπεμπόντων Ἡρακλείδην τῶν πολιτῶν καὶ εὐφημούντων, ὁ δράκων ἀκούσας τῆς ἐπιβοῆς ἐξέδυ τῶν ἱματίων καὶ διετάραξε τοὺς πλείστους. ὕστερον μέντοι ἐξεκαλύφθη πάντα καὶ ὤφθη Ἡρακλείδης οὐχ οἷος ἐδόκει, ἀλλ᾿ οἷος ἦν.”