Serpent's Fang is a legendary item in League of Legends. Serpent's Fang costs 2600 gold and grants 55 Attack Damage, 15 Lethality and a Unique Passive (Shield Reaver).
+55 Attack Damage
Unique - Shield Reaver: Dealing damage to an enemy champion reduces any shields they gain. When you damage an enemy who is unaffected by Shield Reaver, reduce all shields on them.Item performance differs for melee and ranged users.