Special Abilities

 made their debut in Bloons Tower Defense 5. They allow towers to perform powerful skills to stop bloons. Some of these effects last 5-15 seconds, and others do something on the screen instantly, like glueing or freezing all bloons on screen. Special abilities are available after towers are upgraded to Tier Four on the Second Path with the exception of the Banana Farm. Each special ability, when used, has a "cooldown" time before it can be used again, but this cooldown can be reduced with either the "Hotter Cooldown" Premium Upgrade, (-30%) Being in the range of a 4/x Monkey Village, (-20%) or being in the range of a submerged 4/x Monkey Sub. (-15%) (The latter can only take effect on other water based towers) These cooldown reducing effects can stack with each other, greatly reducing the cooldown time of some abilities.

Super Monkey Fan Club (Speed)
This is the special ability for the Dart Monkey. It changes up to 10 dart monkeys into 0/0 Super Monkeys for 15 seconds (3rd in the picture.) 

Blade Maelstrom (Speed / Full-Screen)
This is the special ability for the Tack Shooter. It covers the entire screen with spiralling blades from the tower. (10th in the picture.)

The blades have unlimited popping power, but cannot pop lead. They also spread out the farther they fly away from the tower.

Supply Drop (Money)
This is the special ability for the Sniper Monkey. It calls a familiar-looking plane that flies from the left and drops a crate full of $500 - $1500 cash. (2nd in the picture.)

Turbo Charge (Speed)
This allows the Boomerang Thrower that activated it to attack at hypersonic speeds for 10 seconds. (1st in the picture)

Sabotage Supply Lines (Other)
This is the special ability for the Ninja Monkey. During the sabotage all newly spawned bloons will move at half the speed. (2nd in the picture)

MOAB Assassin (MOAB)
This is the special ability for the Bomb Tower. It fires deadly missiles that targets any MOAB or BFB and destroys that layer instantly. This does 1000 damage to ZOMGs. (Seventh image in the gallery.) It also creates an explosion that does 3 damage to anything in its radius.

Absolute Zero (Whole-Screen)
This is the special ability for the Ice Tower. It freezes the entire sceen for 4 seconds. This does not affect MOAB-class Bloons. (11th in the picture)

Glue Striker (Whole-Screen)
This is the special ability for the Glue Gunner. It glues all the bloons on the screen. This does not affect MOAB class bloons. (6th in the picture)

Monkey Pirates (MOAB)
This is the special ability for the Monkey Buccaneer. It grabs the nearest BFB or MOAB with a harpoon and destroys it along with all bloons inside instantly. This does not affect a ZOMG. (7th in the picture)

Ground Zero (Whole-Screen)
This is the special ability for the Monkey Ace. It drops a bloontonium bomb and deals 350 damage to all Bloons on screen. (4th in the picture)

Bloon Annihilation (Fixed Range)
This is the special ability for the Super Monkey, and for the Phase Crystal in Bloons Monkey City. This destroys all the bloons the ability's  radius, which is as large as the range of a 0/0 Super Monkey. It does 1000 damage to the ZOMG bloon. (5th in the picture) For Phase Crystal's Bloon Annihilation Ability, the cooldown is 10 seconds on normal speed, and 3 seconds on fast forward.

Summon Phoenix (Other)
This is the special ability for the Monkey Apprentice. It summons a phoenix that spits fire at bloons for 20 seconds. (8th in the picture.)

M.I.B Call to Arms (Speed)
This is the special ability for the Monkey Village. It doubles the attack speed and popping power of all towers in range of the village for ten seconds. (12th in the picture.)

Pop and Awe (Whole-Screen + MOAB)
This is the special ability for the Mortar Tower. It immobilizes the bloons and bombards the entire screen with mortar shells for five seconds, popping one layer off every bloon on-screen once per second. MOAB-Class Bloons will also be stunned, though BFBs are stunned for slightly less (2 seconds), and ZOMGs are barely stunned at all (half a second). (2nd to last in the picture.)

Rocket Storm (Other)
This is the special ability for the Dartling Gun. It shoots 5 volleys / pulses of missiles at 100 Bloons each (500 in total) or, if there is less than 100 Bloons on the screen, it will shoot as many rockets as there are bloons on screen. Note that the missiles can still miss their targets. (Last in the picture.)

Orbital Strike (Other)
This is the special ability for the special agent, the Bloonsday Device. For a few seconds a beam controlled by the mouse destroys bloons and does massive damage to MOAB class bloons.

Spike Storm (Whole-Screen)
This is the special ability of the Spike Factory. When used, it covers the whole screen with short-lived spikes (just like in BTD 4).

First Strike Capability (MOAB)
This is the special ability for the Monkey Sub. It fires a devastatingly large missile that targets the largest bloon on screen, destroying up to a ZOMG bloon in one go, or many lesser bloons.

The Swarm! (Whole-Screen)
This is the special ability for the special agent Beekeeper Pro. It makes a swarm of 100 bees that pop bloons the way normal ones do, but disperse after an amount of time.

Activate Sea Monster! (Other)
This is the special ability for the special agent Portable Lake Pro. It creates a tentacle that lashes nearby bloons for 5 seconds. Pops 5 layers off of bloons with unlimited popping power, can pop lead but can't detect Camo Bloons.

Abominable Ability (Speed)
This is for the Mad Snowman pro version appearing in Bloons Tower Defense 5 Deluxe only. It throws snowballs hypersonic for 10 seconds.

Shadow Double (Other)
This is the special ability for the Ninja Monkey. It creates a shadow copy of itself, with identical upgrades. This can be unlocked by the Ninja Academy Specialty Building at Tier 3. It is represented by a white and black shuriken.

Trivia

 * By selling and rebuying towers, it is possible to use a special ability lots of times (unlimited times with Monkey Tycoon). This doesn't work on Supply Drop Snipers, for obvious reasons.
 * This makes Hotter Cooldown much less useful.
 * If there is no MOAB-class Bloon on the screen, the MOAB Takedown Ability will still hook on the strongest Bloon on the screen.
 * Blade Maelstrom has the fastest recharge time and Orbital Stirke has the longest.
 * Oddly, Absolute Zero can freeze White Bloons and Zebra Bloons even without a level 3 Ice Fortress.Fgfhfgh.jpg
 * Perhaps it is so cold that not even they can withstand its arctic temperature.
 * If this were the case, then maybe the MOAB-class bloons have an advanced heating system since they can't be frozen by Absolute Zero.
 * The Banana Farm is the only tower without an ability.
 * The Bloonsday Device (on non-pro & pro), the Beekeeper (pro), the Portable Lake (pro), & the Mad snowman (pro) are the only Special Agents that have a special ability.
 * The Supply Drop Ability is the only ability that has to charge right away, possibly to avoid sell/rebuy abuse to gain unlimited cash.
 * Despite this, the Support Chinook ability doesn't need to charge right away.
 * Most abilities are the last upgrades for path 2 (with the exceptions like for special agents).
 * As of Mar 22, 2012, the Super Monkeys that the Super Monkey Fan Club makes no longer fire triple darts during the ability, nerfing it.
 * Technological Terror only destroys things in a 0/0 Super Monkey range for Bloon Annihilation Ability.
 * The Shadow Double Ability is the only ability that you get from a Specialty Building. However, some tier 4 upgrades in the Mobile version grants some abilities (i.e. Fourth Upgrade Tier for Bombing Range grants a temporary doubled range that could cover the entire track).
 * Precaution: Only save at round 1~46, 49, 59, 69 & 79 or all your special abilities will have to recharge again after you reloaded.
 * The Monkey Beacon from BTD3 and BTD4 sort of has a special ability, Super Monkey Storm.
 * With the Hotter Cooldown and the High Energy Beacon, the Super Monkey Fan Club can be constantly used.
 * The Dart Monkey, Boomerang Thrower, Glue Gunner, and Spike Factory are the only towers who's abilities will change depending on their path 1 upgrades. (And the Shadow Double Ability, but that's a replica of the ninja.)