Editing Lernaean Hydra (section)

==Development of the myth==
The oldest extant Hydra narrative appears in Hesiod's ''[[Theogony]]'', while the oldest images of the monster are found on a pair of bronze [[Fibula (brooch)|fibulae]] dating to c. 700 BC. In both these sources, the main motifs of the Hydra myth are already present: a multi-headed serpent that is slain by Heracles and [[Iolaus]]. While these fibulae portray a six-headed Hydra, its number of heads was first fixed in writing by [[Alcaeus of Mytilene|Alcaeus]] (c. 600 BC), who gave it nine heads. [[Simonides of Ceos|Simonides]], writing a century later, increased the number to fifty, while [[Euripides]], [[Virgil]], and others did not give an exact figure. [[Heraclitus the Paradoxographer]] rationalized the myth by suggesting that the Hydra would have been a single-headed snake accompanied by its offspring.{{sfn|Ogden|2013|p=27–29}}

Like the initial number of heads, the monster's capacity to regenerate lost heads varies with time and author. The first mention of this ability of the Hydra occurs with [[Euripides]], where the monster grew back a pair of heads for each one severed by Heracles. In the ''[[Euthydemus (dialogue)|Euthydemus]]'' of [[Plato]], Socrates likens Euthydemus and his brother Dionysidorus to a Hydra of a sophistical nature who grows two arguments for every one refuted. [[Palaephatus]], [[Ovid]], and [[Diodorus Siculus]] concur with Euripides, while [[Maurus Servius Honoratus|Servius]] has the Hydra grow back three heads each time; the ''[[Suda]]'' does not give a number. Depictions of the monster dating to c. 500 BC show it with a double tail as well as multiple heads, suggesting the same regenerative ability at work, but no literary accounts have this feature.{{sfn|Ogden|2013|p=30}}

The Hydra had many parallels in [[ancient Near Eastern religion]]s. In particular, [[Sumerian religion|Sumerian]], [[Babylonian religion|Babylonian]], and [[Ancient Mesopotamian religion|Assyrian mythology]] celebrated the deeds of the [[List of war deities|war]] and [[List of hunting deities|hunting god]] [[Ninurta]], whom the ''[[Angim]]'' credited with slaying 11 monsters on an expedition to the mountains, including a [[seven-headed serpent]] (possibly identical with the [[Mushmahhu]]) and [[Bashmu]], whose constellation (despite having a single Head) was later associated by the [[Greek astronomy|Greeks]] with the [[Hydra (constellation)|Hydra]]. The constellation is also sometimes associated in [[Babylonian astronomy|Babylonian]] contexts with [[Marduk]]'s dragon, the [[Mushhushshu]].