The largest constellation is named after which mythical creature?

Hydra is the largest of the 88 constellations, measuring 1303 square degrees. It is also one of the longest at over 100 degrees. Its southern end abuts Libra and Centaurus and its northern end borders Cancer. It is commonly represented as a water snake.

Despite its size, Hydra contains only one reasonably bright star, Alphard, designated Alpha Hydrae. It is an orange giant of magnitude 2.0, 177 light-years from Earth. Its traditional name means "the solitary one". Beta Hydrae is a blue-white star of magnitude 4.3, 365 light-years from Earth. Gamma Hydrae is a yellow giant of magnitude 3.0, 132 light-years from Earth.

Hydra’s head is located south of the constellation Cancer and its tail lies between Centaurus and Libra. The constellation was first catalogued by the Greek astronomer Ptolemy in the 2nd century. It represents the Lernaean Hydra from the Greek myth of Heracles’ Twelve Labours. Sometimes it is taken to represent the water snake from the myth about the crow that tried to trick the god Apollo by blaming the snake for its tardiness in fetching the god some water.