Fel orcs are a race of heavily mutated orcs thanks to the Burning Legion. They appear in the "World of Warcraft" series.
The only instance when in which Fel orcs were active on Azeroth was the Third War. Mannoroth tricked Grom Hellscream and his warriors into drinking corrupted blood. Grom later overcome the rage when he ended Mannoroth alongside Thrall and Jaina Proudmoore. This freed a few fel orcs and regular orcs on Draenor. later, when pit lord Magtheridon took over outland, he created fel orcs by making them feast upon his blood. Illidan Stormrage defeated Magtheridon he was imprisoned and the loyal fel orcs watched over the prison. Illidan later completely took the leadership of the fel orcs creating more. Illidan is experimenting this affect on mag'har to create more.
After the Shattering, the fel orcs head back to Azeroth and into the Twilight Highlands. While there, a fel orc by the name of Mor'Ghor and his men take the dragonmaw orcs captive. Adventurers arrive just in time to arm the Dragonmaw clan and end Mor'Ghor's life. The rest of his men then flee or were killed off.
- Fel orc females exist, but they do not appear in-game.