V.A.C.U.M.N.

The V.A.C.U.M.N., or the Very Amazing Crazy Useful Mega Nest, is a blimp with only 3 health, but can only be harmed by certain things. It has the speed of a B.F.B. and first appears on round 73. It does have an ability, however:

Absorb: Uses the four vacumns on it to suck in all projectiles, towers, and agents within a 75px radius of it, including sniper bullets and mortar shells.This is always on. Towers and agents in the V.A.C.U.M.N. will take damage equal to the total damage of all the projectiles in the V.A.C.U.M.N. every 3 seconds. This attack does work on buildings, including TOTMGs.

How to Damage it
Way 1: If at least 1 projectile or monkey is in the V.A.C.U.M.N., and an explosive projectile enters, the explosive projectile has a 20% chance to explode, dealing 15 HP damage to all towers in the V.A.C.U.M.N., destroying all projectiles in it, and dealing 1 damage to the V.A.C.U.M.N. This chance increases by 20% per projectile that enters, capping at 100%. This also works the same way with Troll Towers and other explosive towers, but with an initial chance of 60% instead of 20%. (The percentage boost doesn't apply to road items)

Way 2: If 500 projectiles (towers count as 3 projectiles for every 50px of them) enter the V.A.C.U.M.N., it explodes and dies because it's too full. However, it also destroys all towers, agents, and projectiles inside it.