Neelkanth

During Samudra Manthan, the ocean of the milk was being churned by the devas and asuras, to get Amrit(the elixir of life). 

A dark sticky foam first appeared from the ocean. It was the poison Halahala that had the power to destroy the universe! 

Soon, its fumes started to spread in the air and water and all the creatures started getting affected by it and were on the verge of death. 

Shiva drank it to save the world! Goddess Parvati caught hold of his neck to avoid the poison from entering his body and so it remained in his throat making it blue colored! 

Because of His blue throat, Lord Shiva got the name, Neelkanth!