Black Bloon is an Advanced Blooncard in Bloons Card Storm. When it is destroyed, the player draws one card, provided their hand is not full. Two Black Bloon cards are unlocked by default.
Black Bloon is essentially a White Bloon with more health that delays the card draw, or a Yellow Bloon that costs 2 more, but also draws a card.
Black Bloons cannot be one-shot by Storm Of Arrows unless already damaged by another source such as Quincy's passive.
If your hand has 6 or fewer cards after ending turn with a friendly Black Bloon about to leak, you can assure that the extra card draw will not be wasted. So, on the next turn, both the extra card plus the normal card draw will be gained.
Like most draw cards, Black Bloons are not recommended for aggro due to its inefficient damage for its cost. However, it is helpful for midrange, and its 5 Gold cost is convenient for Bloontonium gains in increments of 5, particularly for Gwendolin and Adora.