Two Faced Bloon
The Two-Faced Bloon is a black-and-white bloon that's constantly spinning around. The black side is immune to physical attacks (explosives, darts, boomerangs, etc...) and the white side is immune to non-physical attacks (spells, lasers, etc...). Together, absolutely no attack is effective for both sides. It takes 7 hits to pop and spawns a Lead Bloon, a Zebra Bloon and an Aqua Bloon when popped.
Bloon Type Pic 2

New pic