Hogaak, Arisen Necropolis is a rare Legendary Creature — Avatar card from Mystery Booster 2 (MB2), collector number 136. Current market price: $1.32, TCGplayer market prices via Scryfall.
You can't spend mana to cast this spell. Convoke, delve (Each creature you tap while casting this spell pays for {1} or one mana of that creature's color. Each card you exile from your graveyard pays for {1}.) You may cast this card from your graveyard. Trample