Invisible Bloon

The invisible bloon is a special bloon type, which only takes 5 hits to pop, but cannot be popped by any tower. The only way to pop them is with road spikes, or spike factories.

Abilities
Cannot be targeted by any tower, not even when they're in range of a 0/3 monkey village.

If one leaks through, you will lose 5 lives, regardless of how damaged it is.