Serpent of the Emerald Sea is a Dota 2 item of Mythical rarity. On DotaLoot you can win it in free giveaways or earn it with Battle Pass levels.
You can get Serpent of the Emerald Sea for free in daily DotaLoot giveaways or with Battle Pass levels. The fastest way is opening cases — noticeably cheaper than buying it on the market.