Hazmonkey

First conception :)

The Hazmonkey is a melee support monkey that has to be placed on the path. It's job is to slow, amplify the damage of other monkeys, and do other miscellaneous jobs.

Base stats

 * Cost : 550
 * Pops 1 layer off any Bloon that passes it.
 * Also slows Bloons that pass it by 25% for 4 seconds.
 * Appearance: A monkey in a hazmat suit standing beside a pile of gray goo. Goo changes colour depending on the upgrades. The latest upgrade determines the colour of the goo.

1. Radioactive waste.
Increases damage to 3 layers for every bloon that passes it. Changes goo colour to dark green.

Costs 350.

2. Uranium waste.
Increases slow to 50% for 5 seconds. Changes goo colour to bright green.

Costs 1000.

3. Plutonium waste.
This tower's slow now affects all bloons, and gives the slow one layer popped per second of slow. Changes goo colour to light blue.

Costs 4000.

4. Polonium waste.
Doubles the damage done to any bloon slowed by this tower from all sources. Changes the goo colour to purple.

Costs 8000.

1. Toxic waste.
You can now sell this tower for 100% of it's cost (including upgrades). Changes goo colour to gold.

Costs 1000.

2. Chemical waste.
Each bloon this monkey pops gives you one bonus cash. Changes colour to bronze.

Costs 1600.

3. Bio-Hazardous waste.
Randomizes the slow amount from 10% to 75% and gives two more bonus cash upon popping a bloon. Changes colour to orange.

Costs 3000.

4. Replicating viral waste.
Each red bloon killed by this tower adds one stack of "replication" to this tower. For each stack of "replication", this tower's slow gets increased by 3 seconds, the damage gets increased by 1 layer, the money-per-pop gets increased by 3, the minimum slow increases by 10%, and the maximum slow increases by 5% (up to a maximum of 50%-75%). When you sell this tower, each stack of replication gives you an extra 300 cash.

Costs 10000.

Please criticize harshly. I will edit this later (maybe).