Kuro Kabuto is a smaller, dark version of the original Kabuto.
It was developed by Usopp during the two year timeskip. It is first clearly seen and named when Usopp fights against the guards of Ryugu Palace. Besides being more easily portable compared to the previous Kabuto (just slightly larger than his old slingshot, the Ginga Pachinko, in its default state), it retains the same design and functions, at least in its standard form. He uses it primarily in conjunction with his Pop Greens and other new attacks, but is also capable of using attacks from his old arsenal. He can also use the larger form of Kuro Kabuto as a close-range weapon to strike opponents.
The Kuro Kabuto can turn into a stronger form called Grow Up Kuro Kabuto (
- Grow Up (
成長Gurōappu?): After feeding Kuro Kabuto some water by connecting a pole filled with water to the base of the handle, Usopp gives it the command "Grow Up" to transform it into its "Grow Up" Kuro Kabuto form. This was first used against some attackers on Punk Hazard. In the Viz manga, it is referred to as Grown Up.
- Totsugeki Ryuseigun (突撃流星群 Totsugeki Ryūseigun?, literally meaning "Charging Meteoric Swarm"): Used in Bakun So form, the slingshot begins to feed on nearby debris before Usopp fires it at his target, pummeling them with a barrage of rocks and rubble. It was first used to defeat Buffalo and capture Caesar Clown by including some seastone handcuffs in the attack. In the Viz manga and FUNimation simulcast subs, this is called Meteor Swarm Assault.
- Super Grow Up (
大成長Sūpā Gurōappu?): A larger version of "Grow Up", that causes Usopp's Kuro Kabuto to become Great Kuro Kabuto (グレート黒カブト Gurēto Kuro Kabuto?). It was first seen when Usopp sniped Sugar from the old Royal Plateau.
- Bagworm (
蓑虫星Baguwāmu?, literally meaning "Bagworm Star"): An extremely long ranged technique designed to incapacitate an opponent. Usopp wraps a payload in a 3-in-1 bullet, comprised of three Kayaku Boshi, whose explosions are used as boosters to gain height, shoot the bullet in different directions or make adjustments to compensate for outside influences such as the wind. With the final booster shooting the bullet directly at the opponent, it opens up, delivering the intended payload. When it was first used, the payload was a recreation of Usopp's horrifying Hissatsu Ganmen Bikkuri Bako face created by Kanjuro's power, used to shock and knock out Sugar.
- Bagworm (
- Further information: Pop Green
After two years of training with Heracles, Usopp has gained mastery of a new type of powerful weapon: the Pop Green. They are seeds of hostile plants that can grow at incredible speed. According to Heracles, these seeds have various uses, especially in combat. Usopp uses these seeds as ammunition for his new slingshot. However, not all these Pop Greens are used for battle purposes, and some can be used for utility functions.
Usopp has a garden on the Thousand Sunny, where he grows new Pop Greens, so they never run out.
The following is a list of techniques that utilize Pop Greens. So far, they have all been called Midori Boshi (緑星 Midori Boshi?, literally "Green Star"), Green Star in the FUNimation adaptations, followed by a specific name.
- Midori Boshi: Devil (緑星・デビル Midori Boshi: Debiru?, literally meaning "Green Star: Devil"): Shooting a Pop Green, Usopp creates a large Venus Flytrap which attacks his enemies. In addition to being able to eat enemies with its large mouth, it can ensnare those nearby with its vines. This was first seen used against Demaro Black, Turco, Chocolat and Mounblutain for harassing the real Nami. In the Viz Manga and FUNimation adaptations, this is called Green Star: Devil.
- Midori Boshi: Sargasso (緑星・サルガッソ Midori Boshi: Sarugasso?, literally meaning "Green Star: Sargasso"): Usopp fires a Pop Green at his target, which then explodes into an array of resilient seaweed, strong enough to delay an avalanche of rock and earth. This was first used in order to protect the Thousand Sunny from an undersea avalanche. The name is similar to the Sargasso Sea, a region of the North Atlantic Ocean where ships often become tangled in weeds. In the FUNimation simulcast subs, this is called Green Star: Sargasso.
- Midori Boshi: Rafflesia (緑星・ラフレシア Midori Boshi: Rafureshia?, literally meaning "Green Star: Rafflesia"): Usopp fires a Pop Green that reveals a rather large Rafflesia flower. The flower then excretes a foul smelling odor, disabling the enemy's senses with its stench. This was first used against Hody Jones and his men. In the FUNimation adaptations, this is called Green Star: Rafflesia. In One Piece: Pirate Warriors 3 it appears as Usopp's unique action, however in the game the flower poisons nearby enemies (likely used as a replacement for its foul odor) and produces a massive explosion if hit by any of Usopp's fire-based attacks such as Flaming Star or Fire Bird Star (basically serving the same function as his Pre-timeskip unique actions, Special Oil Star and Breath Dial as they also explode when hit with Usopp's fire-based attacks).
- Midori Boshi: Take Jave-rin (緑星・竹ジャベ林 Midori Boshi: Take Jaberin?, literally meaning "Green Star: Bamboo Javelin-Grove"): Usopp shoots a Pop Green at the ground, causing stalks of bamboo to shoot up from the ground, stabbing and impaling anyone it crosses paths with. The name is a pun and portmanteau of "javelin" and "rin" (林 grove?). It was first used against some of the New Fishman Pirates. This is called Green Star: Bamboo Javelin in the Viz manga and FUNimation sub.
- Midori Boshi: Dokuro Bakuhatsu So (緑星・ドクロ爆発草 Midori Boshi: Dokuro Bakuhatsu Sō?, literally meaning "Green Star: Skull Exploding Grass"): Usopp shoots a Pop Green that explodes upon impact. It releases a large red explosion in the shape of a skull. It was first used to get Daruma out of the ground by literally blowing him out of the tunnel system he dug. This is called Green Star: Skull Bombgrass in the Viz manga and FUNimation dub. In the FUNimation subs, this called Green Star: Skull-Blast Grass.
- Midori Boshi: Humandrake (緑星・ヒューマンドレーク Midori Boshi: Hyūmandorēku?, literally meaning "Green Star: Humandrake"): Usopp shoots a Pop Green on the ground that only triggers to attack opponents once they step on it, leaping off and entangling them with its roots, causing them to get off balance. It is first used against Daruma to lure him in the "Trampolia". This is a pun to "human" and "mandrake". This is called Green Star: Humandrakes in the Viz Manga.
- Midori Boshi: Trampolia (緑星・トランポリア Midori Boshi: Toranporia?, literally meaning "Green Star: Trampolia"): Usopp shoots a Pop Green on the ground that launches anyone who gets close to it up into the air. It is shaped like a big flower with a bubble at the center. It was first used in conjunction with "Humandrake" against Daruma. In the Viz Manga and FUNimation adaptations, this is called Green Star: Trampolia.
- Midori Boshi: Impact Wolf (緑星・
衝撃狼草Midori Boshi: Inpakuto Urufu?, literally meaning "Green Star: Impact Wolf Grass"): Usopp shoots a Pop Green into the air which then sprouts into grass that takes the shape of a wolf. The bulb where it came from that shaped like a wolf's nose can release a stunningly powerful shockwave that is three meters in diameter, which can shock an opponent. It is first used in coordination with the combination of "Humandrake" and "Trampolia" for an accurate hit against Daruma.
- Midori Boshi: Boaty Banana (緑星・ボーティーバナナ Midori Boshi: Bōtī Banana?, literally meaning "Green Star: Boaty Banana"): Usopp shoots a Pop Green onto the water that turns into a banana-shaped boat. The boat is shown to be quite durable, withstanding the boiling water of a lake found on Punk Hazard. The name is possibly a pun on "Banana boat". In the Viz Manga and FUNimation dub, this is called Green Star: Boaty Banana.
- Midori Boshi: Uchiwa So (緑星・団扇草 Midori Boshi: Uchiwa Sō?, literally meaning "Green Star: Fan Grass"): Usopp shoots a Pop Green which sprouts tall grass that looks like uchiwa fans on one end of it. It was first seen in Punk Hazard Island to use as oars in conjunction with the "Boaty Banana" to cross the lake. An "uchiwa" is a non-bending hand-held fan primarily used for cooling oneself in hot weather. This is called Green Star: Fan-Grass in the Viz Manga.
- Midori Boshi: Platanus Shuriken (緑星・プラタナス手裏剣 Midori Boshi: Puratanasu Shuriken?, literally meaning "Green Star: Platanus Shuriken"): Usopp fires a Pop Green that sprouts into several star shaped plants that cut at the opponent. This was first used against Trebol. Platanus is a genus of trees that have jagged star-shaped leaves.
- Midori Boshi: Nemuri So (緑星・眠り草 Midori Boshi: Nemuri Sō?, literally meaning "Green Star: Sleeping Grass"): Usopp fires a Pop Green that sprouts a flower, which then releases some sort of sleeping gas, putting those nearby into sleep. First used against some Beasts Pirates guards at Onigashima. In the VIZ Manga, this is called Green Star: Sleep-Grass.
- Midori Boshi: Hanabibana (緑星・花火花 Midori Boshi: Hanabibana?, literally meaning "Green Star: Fireworks Flowers): Usopp fires a Pop Green that sprouts several flowers onto the target, which then detonate into searing hot, bright explosions resembling fireworks. It was first used against Page One when he took ahold of Komachiyo, being strong enough to throw him off. In the VIZ Manga, this is called Green Star: Firework Flowers.
- Midori Boshi: Baku Bokkuri (緑星・爆ボックリ Midori Boshi: Baku Bokkuri?, literally meaning "Exploding Pinecones"): Usopp fires a Pop Green that sprouts into several pine cones that act similar to grenades, exploding after a set amount of time. It was first used against Page One with the intent of finishing him off, but the Tobiroppo was tough enough to resist the explosion. In the VIZ Manga, this is called Green Star: Exploding Pine Cones.
- Midori Boshi: Sprinkler (緑星・スプリンクラー Midori Boshi: Supurinkurā?): Usopp fires a Pop Green that sprouts a flower which spins and sprays water in every direction. It was first used to combat the fire raging in Onigashima; however, it could not generate enough water and was quickly consumed by the blaze.
Anime Only Techniques
- Midori Boshi: Sea Devil: Similar to Midori Boshi: Devil, this plant floats on the sea, and is capable of swallowing the opponent along with boats. This was used against the Silver Pirate Alliance, who attacked using Battle Boats.
- Yabusame Devil (ヤブサメデビル Yabusame Debiru?, literally meaning "Shark-Arrow Devil"): Similar to Midori Boshi: Devil, the Pop Greens are fired off more rapidly, and the plants in question have a sleeker look in comparison to the normal Devil. Usopp used this move against the Long Long Pirates. In the FUNimation dub, this is called Shark-Arrow Devils.
- Midori Boshi: Cushion Kazue (Midori Boshi: Cushion Kazue?, literally meaning "Green Star: Cushion Vine"): Usopp fires a Pop Green that sprouts into a net of vines, that can cushions the impact of things that crash into it. It was used to save Chopper and the Minks when the boat they were treating Zunesha on was about to crash into the elephant's leg due to a sudden squall.  In the FUNimation dub and sub, this is called Green Star: Cushion Vine.
- Midori Boshi: Hebi Hanabi (Midori Boshi: Hebi Hanabi?, literally meaning "Green Star: Snake Fireworks"): Usopp plants several Pop Greens on a target which stays as seeds until it receives a powerful impact. The seeds will then quickly grow into several thick, powerful green vines which wraps itself around a target with enough strength to cleanly snap off Busoshoku Haki enhanced machinery. It was used against Douglas Bullet to destroy his transformed ship and was activated by Luffy.
- Hisatsu Midori Boshi: Dokuro Bakuhatsu So (必殺緑星・ドクロ爆発草 Hisatsu Midori Boshi: Dokuro Bakuhatsu Sō?, literally meaning "Sure-Kill Green Star: Skull Exploding Grass"): A variant of Midori Boshi: Dokuro Bakuhatsu So was used during the milestone Episode 1000, with the only difference being clouds forming the number 1000 above the skull. Usopp himself states, "It's an exclusive version for this occasion."
- Bakusui Boshi (爆睡星 Bakusui Boshi?, literally meaning "Burst Sleep Star"): Usopp shoots a pellet which releases a powerful sleeping gas. It was first used to sedate the berserk children on Punk Hazard. However, its effectiveness weakens when it is used repeatedly on the target. In the Viz manga and FUNimation simulcast subs it is called Sleep Star.
- Fire Bird Star (
火の鳥星Faia Bādo Sutā?): Usopp can still use his Fire Bird Star even with his Kuro Kabuto. The color of the fire bird seems to be changed. Despite not being dressed as Sogeking, Usopp said the name of the attack in English when using Kuro Kabuto to perform it. After the timeskip this was first seen being used against Caesar Clown in a failed attempt to ignite the man's gases.
- Seastone Handcuffs: Used against opponents with Devil Fruit abilities, the handcuffs both neutralize the opponent's power, as well as strangle them with the chain. Usopp found these handcuffs after searching Caesar's lab on Punk Hazard. It was first used against Caesar when he tried to run away from them.
- Kibi Dan-boshi (きびだん星 Kibidan Boshi?): Used against Gifters, Usopp targets their mouths and fires Tama's kibi dangos, which tame both animals and people who have eaten successful SMILEs, making them subservient to Tama. This is called Millet Dumpling Star in the Viz Manga.
- Atlas Suisei (アトラス彗星 Atlas Suisei?, literally meaning "Atlas Comet"): Usopp can still use the Atlas Comet even with his Kuro Kabuto. He shoots four high speed Kayaku Boshi with smoke tails which converge together and hit a target. This attack was used in the anime against Orochi's forces.
- In response to a reader request, Oda drew anthropomorphic versions of the Kuro Kabuto and Usopp's clasped bag. In the illustration, Kuro Kabuto appears as "Black", a man dressed like a superhero with a suit, a cape and a mask. His hair is shaped like the horn of a rhinoceros beetle (kabutomushi).