Pioneer Original

Pioneer Original, the Initial Tower is a new Hero, mainly composing of parts from the 5 first towers of the BTD series (Dart Monkey, Tack Shooter, Ice Monkey, Bomb Shooter, Super Monkey).

At Level 0, Pioneer Original just throws darts, as if it were a medium-ranged Dart Monkey. To compensate, Pioneer is the fastest upgrading Hero, requiring the least XP to upgrade out of all the Heroes.

Appearance
Pioneer has the appearance of a Dart Monkey wearing a blue and red t-shirt with a Super Monkey icon, and with a cap modeled as a Tack Shooter. Pioneer also has a Bomb Shooter strapped to their back. They have the arms of an Ice Monkey and their left eye is replaced with a Tack Shooter barrel.

Upgrades
Level 1 - Has a chance to throw tacks, which have more pierce than darts.

Level 2 - Increased chance to throw tacks.

Level 3 - Immunity Bypass Ability: Can pop 3 layers of bloon and attacks can affect any bloon for 10 seconds.

Level 4 - Faster attack speed.

Level 5 - Detects camo.

Level 6 - Has a chance to throw ice pellets, which can freeze and pop bloons.

Level 7 - Increased ice pellet freezing duration.

Level 8 - Has a chance to throw bombs, which explode.

Level 9 - Bombs have bigger explosions.

Level 10 - Originalize Ability: Do 50 damage to any bloon that wasn't in BTD1. (in other words, any bloon that isn't Red Bloon, Blue Bloon, Green Bloon, Yellow Bloon, Black Bloon, or White Bloon)

Level 11 - Replaces ice pellets with ice-tipped darts, which freeze and pierce through bloons.

Level 12 - Tacks are heated into Hot Shot Tacks, searing through Lead Bloons.

Level 13 - Replaces bombs with explosion-laced darts, which explode on their last pop. Regular darts are not thrown anymore.

Level 14 - 3 tacks are thrown at a time, akin to Dart Monkey's Triple Darts.

Level 15 - Immunity Bypass Ability has reduced cooldown, pops 5 layers, and duration is increased to 20 seconds.

Level 16 - Has a chance to swiftly shoot a stream of 20 darts, akin to Super Monkey.

Level 17 - Ice-tipped darts freeze a group of bloons upon making contact with a bloon.

Level 18 - Originalize Ability has reduced cooldown and does 100 damage to M.O.A.B-Class Bloons.

Level 19 - Explosion-laced darts do 20x damage to M.O.A.B-Class Bloons.

Level 20 - Originalize Ability does 300 damage against M.O.A.B-Class Bloons.

In-Game Quotes
Upon placing on the map: When selected: When leveling up: When M.O.A.B-Class Bloons appear: When popping a M.O.A.B-Class Bloon: When using an ability: When a bloon leaks:
 * "Yay."
 * "Meh."
 * "Ouch."
 * *cough*
 * *sneeze*
 * *clears throat*
 * "Hmm?"
 * "Yesh?"
 * *sniff*
 * *sigh*
 * "Darts."
 * "Tacks."
 * "Ice."
 * "Bombs."
 * "Huh?"
 * *slowly exhales*
 * "Woo hoo."
 * "What? I wasn't looking."
 * "Great! Now go outside for once!" - Level 20
 * "That's no ordinary Blue Bloon." -M.O.A.B appearance
 * "This giant Red Bloon should be easy, right? -B.F.B appearance
 * "Green Bloons are getting big these days." -Z.O.M.G appearance
 * "What? I don't see anything!" -D.D.T appearance, if below Level 5
 * "There's a big fast Black Bloon approaching!" -D.D.T appearance, if Level 5 or higher
 * "Whoever heard of a big Purple Bloon?" -B.A.D appearance
 * "Looks like the Red Bloons, Blue Bloons, and Green Bloons have all teamed up." -E.V.I.L appearance
 * "What was that?"
 * "Bloons sure let themselves go these days."
 * "What immunities?" -Immunity Bypass
 * "Ack!"
 * "Oopsies!"

Trivia

 * Pioneer's unawareness of M.O.A.B-Class Bloons and Purple Bloon is a reference to there being no M.O.A.B-Class Bloons or Purple Bloons in BTD1.