When an orc slays an elf in Gruumsh’s name and offers the corpse of its foe as a sacrifice to the god of slaughter, an aspect of the god might appear. This aspect demands an additional sacrifice: one of the orc’s eyes, symbolizing the loss Gruumsh suffered at the hands of his greatest enemy, Corellon Larethian.

If the orc plucks out one of its eyes, Gruumsh might grant the orc spellcasting ability and special favor, along with the right to call itself an Eye of Gruumsh. When not using their auguries to advise their war chiefs, these savage devotees of the god of slaughter hurl themselves into battle, their weapons stained with blood.

Aggressive. As a bonus action, the orc can move up to its speed toward a hostile creature that it can see once per hostile encounter. 

Gruumsh’s Fury. The orc can dual wield special weapons that can be 1 handed. 

Ritual Scarring. Beginning at 3rd level, you gain proficiency in the Intimidation skill if you didn't already have it. You add double your proficiency bonus to charisma checks against orcs. These scars are recognized as a symbols of great religious status by all orcs and half-orcs.

Spellcasting. The orc is a 3rd-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 11, +3 to hit with spell attacks). The orc has the following cleric spells prepared:
Cantrips (at-will): guidance, resistance, thaumaturgy
1st level (4 slots): bless, command
2nd level (2 slots): augury, spiritual weapon (spear)

Gruumsh One-Eye. Orcs worship Gruumsh, the mightiest of the orc deities and their creator. The orcs believe that in ancient days, the gods gathered to divide the world among their followers. When Gruumsh claimed the mountains, he learned they had been taken by the dwarves. He laid claim to the forests, but those had been settled by the elves. Each place that Gruumsh wanted had already been claimed. The other gods laughed at Gruumsh, but he responded with a furious bellow. Grasping his mighty spear, he laid waste to the mountains, set the forests aflame, and carved great furrows in the fields. Such was the role of the orcs, he proclaimed, to take and destroy all that the other races would deny them. To this day, the orcs wage an endless war on humans, elves, dwarves, and other folk.

Orcs hold a particular hatred for elves. The elven god Corellon Larethian half-blinded Gruumsh with a well-placed arrow to the orc god’s eye. Since then, the orcs have taken particular joy in slaughtering elves. Turning his injury into a baleful gift, Gruumsh grants divine might to any champion who willingly plucks out one of its eyes in his honor.