Where is it?

Boss in Wailing Caverns. See the boss's loot on the instance page.

Drops

From EG Link (collected in Forever by other players, not confirmed with Forever Scout): share of 5 opened loot windows.

Item	Chance	Source
Stinging Viper	60%1 in 2 (3/5)60% chance (1 in 2) – common (3/5)
Gem of Pythas	60%1 in 2 (3/5)60% chance (1 in 2) – common (3/5)
Armor of the Fang	40%1 in 3 (2/5)40% chance (1 in 3) – common (2/5)