|“||Gwendolin believes there hasn't yet been a Bloon problem that can't be solved with fire. Lots of fire.||”|
|~ Bloons TD6|
Gwendolin is a Hero in the game Bloons TD 6. She specializes in fire-based weaponry and is unlocked at experience level 14. She has short range, and her main attack is a medium-range fire blast from her flamethrower whose shots can pierce up to 3 Bloons. Due to her attack being fire based, she cannot pop Purple Bloons, at least until level 16. She is also unable to pop Camo Bloons without support, except with her abilities.
She costs $765 on Easy, $900 on Medium, $970 on Hard, and $1,080 on Impoppable.
In the 6.0 update, she was given a new skin, named Scientist Gwendolin, with new voice lines and appearance. She wears a blue and white lab tunic and her hair is blue instead of orange. She holds a purple potion instead of her normal fuel. The skin costs 2500 to unlock.
Gwendolin will start upgrading herself every round upon placement. She earns more XP each round to unlock her next upgrade irrespective of how many bloons she pops. Her upgrades can also be immediately bought with cash, though the amount of cash required to purchase the next upgrade will typically increase as the upgrades get higher, making self-upgrading an important element for her overall power.
The following are the upgrades and their XP required to level up:
- Level 1 - Blasts Bloons with fire from her flamethrower.
- Level 2 - Slightly increases popping power and range.
- Level 3 - Unlocks Cocktail of Fire.
- Level 4 - Unlocks "Heat It Up," a passive ability that periodically creates a powerful blast of fire around Gwendolin that pops Bloons, and adds fire to nearby Monkeys' attacks. This occurs every 30 shots she makes. This buff allows nearby affected towers to pop lead bloons and gives them +1 pierce.
- Level 5 - Increased popping power.
- Level 6 - Attacks can sometimes cause a burn effect on a targeted bloon.
- Level 7 - Increased range for "Heat It Up."
- Level 8 - Shoots two flames per shot.
- Level 9 - Initial hit for every blast pops one extra bloon layer.
- Level 10 - Unlocks Firestorm.
- Level 11 - Increased attack range.
- Level 12 - Increased attack speed.
- Level 13 - Greatly increased popping power.
- Level 14 - Cocktail of Fire does extra damage.
- Level 15 - Increased attack speed.
- Level 16 - Allows Gwendolin to pop Purple Bloons, and Firestorm lasts longer.
- Level 17 - Heat It Up empowers affected monkeys to pop 1 extra layer, and do +2 damage to Lead Bloons.
- Level 18 - Increased attack speed.
- Level 19 - Shoots 3 blasts of fire per shot.
- Level 20 - Firestorm does hugely increased damage. The flames now inflict multiple layers of damage at a time to bloons and do 25 damage per second to MOAB class.
- Cocktail of Fire - Throws a molotov cocktail, which generates a fiery explosion that burns any Bloon that passes through the flames, and will continue to burn for about half the cooldown of the ability. When bloons are in Gwendolin's range, she aims it at the furthest bloons advanced. When there are no bloons in her range, or if there are camo bloons that she cannot detect, she throws the cocktail to a random spot in her range.
- Firestorm - Covers the entire screen with fire, igniting all bloons. Burns about 2 layers per second and does 10 damage per second to MOAB class bloons. Increases burn to 5 damage per half a second on normal bloons and 25 damage to MOAB-class per second at Level 20.
Ever since her nerf in 6.0, she has never been as good as she once was. While she is able to still buff towers, her Heat it Up uptime is far less and difficult to utilise fully. Despite that, she is not all flawed as she still maintains a high level of DPS, despite possibly being outclassed by Captain Churchill in this regard. She also has amazing abilities. Cocktail of Fire will deal with a short burst of bloons while Firestorm is an easy emergency button that deals massive damage.
One of her main advantages comes from beating difficult Ceramic Bloon rounds on her own at Level 10+, especially to the likes of Rounds 63, 76, and 78. With effective ability timing, she can help beat various difficult grouped bloon rounds with ease.
- Her burn effect is a powerful ability she gains early on, putting her on 'Strong' targeting allows her to tear through early rounds, including popping leads, but be careful to defend from Purple Bloons.
- Cocktail of Fire is a very powerful ability, being able to destroy entire Rainbow Bloons, however targeting is random and often unreliable for targeting bloons that have escaped through the primary chokepoint. (However she will throw the cocktail on the bloons she is targeting so timing it will can be very helpful)
- Once Gwendolin hits level 17, her Heat It Up ability gives +1 layers of damage to all nearby towers, useful to buff nearby towers. Do make sure she is attacking as she needs to attack for Heat It Up to activate. Placing her near the front (but not directly at the front) should allow her to activate her Heat It Up effect as often as possible.
- Heavy ceramic rushes (especially on Round 63, 76 and 78) can be stopped very quickly with Cocktail of Fire and Firestorm.
- For Round 63, placing a Cocktail onto the first wave then activating Firestorm on the second wave and then activating another Cocktail on the third wave should eliminate Round 63 with relative ease, but requires good ability timing.
- For Round 76, she can activate her Firestorm can effectively cancel out the regrowth, burning the bloons faster than they can be regenerated.
- For Round 78, she can easily use two Firestorms for both waves, as her Firestorm ability only has a cooldown of 60 seconds.
- Firestorm does 25 damage at level 20, dealing heavy damage to all blimps and bloons on screen.
When you place her on the map:
- "With enough fuel and air, everything burns!"
- "We have ignition!"
When selecting her:
- "Fired up!"
- "What next?"
- "What's up?"
- "I wouldn't do that if I were you." (when annoyed)
- "You're on my list now!" (when annoyed)
When leveling up:
- "All right!"
- "Oh, sweet!"
- "Oh yeah!"
- "It doesn't get hotter than this!"- Level 20
When MOAB Class Bloons appear:
- "MOAB! Burn it!"- MOAB appearance
- "BFB! Burn it!"- BFB appearance
- "ZOMG! Burn it!"- ZOMG appearance
- "DDT! Burn it!"- DDT appearance
- "BAD? Gonna need more gas!" - BAD appearance
When popping a MOAB Class bloon:
When using an Activated Ability:
- "Fire bomb!" - Cocktail of Fire
- "It's all on fire now!" - Firestorm
When leaking a bloon:
- "They're leaking!"
- "Stop them!"
Scientist Gwendolin has a different set of voice lines.
- "I like blue hair... and blue fire!"
- "I've made some minor modifications!"
When you select her:
- "Hello!" (excited)
- "Hello!" (less excited)
- "Can I help you?"
- "Office hours!"
- "This is it!"
- "What?!" (when annoyed)
- grunts* "I'm thinking!" (when annoyed)
When leveling up:
- "This.. is incredible!"
- "Firestorm maxed! Let's use it! " - level 20
When MOAB class bloons appear:
- "That.. looks very flammable!"
When popping a MOAB class bloon:
- "Aww.. no hydrogen!"
When using an activated ability:
- "I'll put this here!" - Cocktail of Fire
- "You said Firestorm?" - Firestorm
When leaking a bloon:
- "No.. no... NO!"
Scientist Gwendolin Skin added
Gwendolin's Heat It Up will trigger less often and will no longer refresh while Heat It Up is already in effect.
Gwendolin's burn effect on MOAB-class bloons will now display fire on affected MOAB-class.
Level 17 Heat It Up now grants an extra +1 damage to Lead Bloons
Level 10 Firestorm ability now also applies Heat It Up to all towers when activated
Level 14 now also adds a Damage Over Time application to the Cocktail of Fire ability. This also applies 50 damage over 10 seconds to any MOAB Class Bloons that are hit. Normal napalm is applied to all other bloons.
- At launch, Gwendolin was the only fully confirmed female monkey in the series. Prior to BTD6, the monkeys were male/female neutral, although Dart Monkey and Wizard Monkey are male in the Super Monkey Fan Club description and Wizard's name. Female monkeys also exist in Bloons Adventure Time TD.
- As of update 14.0, the patch notes monkey, as well as Ezili and Adora, are also female.
- It has been confirmed that all monkeys except for heroes and the patch notes one are all genderless. 
- Gwendolin was originally the only Hero to have her name spelled in yellow instead of blue in the preview images and wallpapers. This was changed in v14.0 when Adora was added.
- As with Quincy, Gwendolin's in-game quotes confirm the correct pronunciation of the MOAB Class Bloons; MOAB is said as one word (pronounced as "moh-AB"), while the BFB, ZOMG, DDT, and BAD are pronounced by their initials.
- Gwendolin used to be the most expensive hero, costing $900 on Medium. With the 2.0 update, Captain Churchill became the most expensive hero, costing $2000 on Medium.
- Whenever a MOAB-Class bloon appears, she always says "Burn it!", except for when a B.A.D. shows up.
- One of Gwendolin's in-game quotes, "With enough fuel and air, everything burns!" is a possible reference to the Joker's quote from The Dark Knight; "Everything burns!"
- Before 6.0, you could get Gwendolin to throw three Cocktails of Fire instead of one by having all Monkey Knowledge in the Heroes section and placing her near a 5/X/X Monkey Sub.
- Gwendolin had made appearance in one of Ninja Kiwi's Facebook account posts regarding July 4th 2019. She is seen roasting grilled pineapples on the barbecue at night. She also holds a spatula and a glass of orange juice while a fireworks display is set, This Could Be A Reference To The Premium Upgrade In BTD5, Link(Facebook Post).