Monkey Engineer (BTD7)

The Monkey Engineer is a returning tower from Bloons TD 6. He shoots nails that can pierce through 4 Bloons each and with the right upgrades, can build independent sentries, make Bloon traps that can be disposed of for cash, and fire foam that removes Lead and most properties. His ability at x-4-x will increase the stats of a tower chosen by the player for 45 seconds. Tier 5 and 6 improve the stats and duration. Tier 5 increases the duration to 60 seconds and Tier 6 also influences nearby towers with the same buff and increases the duration to 90 seconds. The other Tier 6 upgrades allow the engineer to make radioactive sentries that explode with high force when they collapse or huge batteries that flatten Bloons for streams of money. A Monkey Engineer costs $380 in easy, $450 in medium, $485 in hard, and $540 in impoppable.