Buy @ TCGplayer
Chroma — Umbra Stalker's power and toughness are each equal to the number of black mana symbols in the mana costs of cards in your graveyard.
Chroma abilities check only mana costs, which are found in a card’s upper right corner. They don’t count mana symbols that appear in a card’s text box.
Chroma abilities count hybrid mana symbols of the appropriate color. For example, a card with mana cost {3}{U/R}{U/R} has two red mana symbols in its mana cost.
This is a characteristic-defining ability, which means it functions in all zones. You include the symbols in the Stalker’s own mana cost if you need to determine its power and/or toughness while it’s in the graveyard.
