Book of Mazarbul is a uncommon Enchantment — Saga card from The Lord of the Rings: Tales of Middle-earth (LTR), collector number 567. Current market price: $0.42 (foil $0.46), TCGplayer market prices via Scryfall.
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I — Amass Orcs 1. (Put a +1/+1 counter on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.) II — Amass Orcs 2. III — Creatures you control get +1/+0 and gain menace until end of turn.
All The Lord of the Rings: Tales of Middle-earth cards and prices