Hyginus Fabulae, 32
Megara.

When Hercules had been sent by King Eurystheus to the three-headed dog, Lycus, Neptune's son, thinking that Hercules had perished, desired also to murder Megara, Creon's daughter, Hercules' wife and his sons Therimachus and Ophites, and he planned thereby to take the kingship.
Hercules interceded and killed Lycus. Afterwards, when in a fit of rage cast upon him by Juno, Hercules killed Megara and his sons Therimachus and Ophites.
After he recovered his wits, he sought an oracle from Apollo as to how he might expiate the crime. Because Apollo refused to offer a response to him, Hercules burst into anger and took Apollo's tripod from the sanctuary, and he commanded the unwilling god to produce the oracle. Hercules, according to this response, was given by Mercury into servitude to Queen Omphale.
—— trans by RTM


megara.

Hercules cum ad canem tricipitem esset missus ab Eurystheo rege et Lycus Neptuni filius putasset eum periisse, Megaram Creontis filiam uxorem eius et filios Therimachum et Ophiten interficere uoluit et regnum occupare.
Hercules eo interuenit et Lycum interfecit: postea ab Iunone insania obiecta, Megaram et filios Therimachum et Ophiten interfecit.
postquam suae mentis compos est factus, ab Apolline petiit dari sibi responsum quomodo scelus purgaret; cui Apollo sortem quod reddere noluit, Hercules iratus de fano eius tripodem sustulit, quem postea Iouis iussu reddidit, et nolentem sortem dare iussit.
Hercules ob id a Mercurio Omphalae reginae in seruitutem datus est.


Hyginus Astronomus Poet. Astron. 2.14.2
Other [astronomers who define the constellation Ophiuchus] say that it is Hercules killing the snake in Lydia at the River Sagaris. He killed many people and was making prayers with grain offerings on the riverbank. For this deed, Omphale, who was then queen of Lydia, sent Hercules back to Argos laden with many gifts; later he was set by Jupiter among the stars on account of his heroism (i.e. his "fortitudo"). — trans by RTM
Alii autem Herculem esse demonstrant, in Lydia apud flumen Sagarim anguem interficientem, qui et homines complures interficiebat et ripam frugibus orbabat. Pro quo facto ab Omphala, quae ibi regnabat, multis ornatum muneribus Argos remissum, ab Ioue autem propter fortitudinem inter sidera conlocatum.