The slime contained is ravenous and uncontrollable, devouring party members and dealing damage to them. Only usable outdoors in the Shadowlands. Phial of Ravenous Slime drops from Vat of Conspicuous Slime Treasures of Maldraxxus in the Maldraxxus zone.
Here you can buy Phial of Ravenous Slime Toy Boost for EU or US Servers.
You'll get guide for completing Phial of Ravenous Slime Toy Boost