It is immune to freezing - It is immune to less effects that towers and upgrades have.
It moves twice as fast as a Red Bloon, and faster than a Black.
They are encountered later in the games.
It could be said that the Black Bloon was formerly more powerful than the White Bloon, and thus was once the most powerful Bloon. In BTD1, only Bombs could pop frozen Bloons, so you needed bombs to have any use for Ice Towers. Also, since BTD1 does not have Snap Freeze, the Ice Tower could not deal damage. Because of this, more people used Bombs back then, and thus more people were affected by the Black Bloon's immunity to explosions.
In BTD3 and BTD4, a single pile of Road Spikes can almost take down an entire Black Bloon, leaving only a Red Bloon. In BTD5, one spike pile can pop a Black Bloon whole.
It is sometimes confused with the Bomb Bloon. Both deal with Bombs in some way.
In BTD1 and BTD2, because of its resistance to bombs, it is impossible to win the game using only Bomb Towers. In BTD3, BTD4 and BTD5, it is possible because of the Frag Bombs upgrade, and also, in BTD5, the Bloon Impact upgrade.
Strangely, Black (and also White) Bloons are small, yet containing two larger (Pink) Bloons.
However, when they have Regen properties, this issue is cleared up, as all Regenerating Bloons have the same size.
If the player upgrades a Frag Bombs tower to a Cluster Bombs tower, the tower will not be able to pop Black Bloons anymore until upgraded to Bloon Impact, because the frags are turned into bombs.
In BTD1, Black Bloons can not be popped at all while frozen because they are immune to Bombs, while frozen Bloons are immune to everything except Bombs.
There are 4 Bloon types in the entire Bloons series that have multiple "parents" - Black Bloons, Ceramic Bloons (however, they also released from DDT on Bloons Monkey City, but with Camo and Regen properties) and Pink Bloons. The Black Bloon has the Lead Bloon and the Zebra Bloon and the Ceramic Bloon has the MOAB and the DDT. There are 2 of them that have 3 "parents" - Black Bloons and Pink Bloons (whose parents are Blacks, Whites and Camouflage Bloons in BTD4.
The Black Bloon and the White Bloon are the only Bloons smaller than the Bloons they spawn.