Snake Tongue

Gather some Jellyfish Slime from Venomous Cnidaria and Snake Venom from Horned Vipers and bring them to Sea Master on the Isle of Singing Water.

I have the toughest trial for you. Many brave warriors met their death trying to complete this laborious task. However, those who fear danger shall not have my blessing. Now listen to my will and perform it exactly that way!
There are lots of venomous reptiles in the world, and each of them has a purpose, a place in the circle of life, each makes way for another life with that of its own. There are those, however, driven by death alone who strive to spoil the vortex of life with their venom. Death-Adder is its name, and there's nothing better for it than turning life into death. However, that serpent is extremely cunning and only able to attack on the sly. Your task is to lure it. And to make a bait for the venomous reptile, you will need another type of venom. Although it is not so strong, its filthy stench is to that reptile like heavenly fragrance...

I weed out the field in pain, protecting myself against a greater pain...

Here it is, the filthy liquid that brings death to all living beings. However, just like death is followed by life, this venom will be used to the benefit of life, too.