Similar to Part 4's Echoes, Tusk takes various forms, or "ACT"s. Like other Stands such as Dragon's Dream or Cinderella, Tusk's abilities are intimately linked with a supernatural phenomenon inherent to the world of JoJo's Bizarre Adventure, namely the Spin.
Manga Debut: SBR Chapter 25, Tusk (1)
ACT1 resembles a small, neotenous animal. Its head is of equal or slightly greater size than its body, and it floats with two short, vague, and inarticulate arms and one such leg. Its posterior is marked somewhat irregularly by small stars, behind which dark circles radiate to their points; while four tendrils droop from the base of its trunk to the approximate length of its leg, bearing heart shapes.
On its head, it bears two long, mammalian ears; small, reflective black eyes, under a brow of a troubled angle; a large star at the top of its forehead, behind which a dark circle radiates to its points, and from the center of which a string links with the tip of a cone fastened to the region of its nose. Eight wavering vestiges emanate from its head laterally: Two above; four from its sides, the lower of which, at its cheeks, are also surrounded by a dark circle; and one either side of its chin.
It was designed with an axolotl in mind.
Tusk ACT1 possesses sentience separate from Johnny, as it is the guardian of the Left Arm. It decides to appear to Johnny and independently help him.
ACT1 occasionally produces the sound "chumimi~in".
Despite having a corporeal form, Tusk's power functions as a supernatural ability that Johnny must use personally to fight like a gunman. Tusk ACT1 is overall quite weak and isn't sufficient to challenge most Stand users.
Johnny is able to make his fingernails, and later toenails, spin themselves at a high velocity, and shoot them like bullets up to 10 meters. The nails have incredible cutting power, capable of slicing through rock, cutting limbs clean off, or carving a tree into a humanoid shape within seconds. However, they do not possess the power to cut through metal. Once Johnny shoots a fingernail, they take a short time to grow back.
Occasionally, Johnny lets the nails stay on his fingers. When he puts the nails against the ground, their rotating movement can rapidly carry Johnny away from his current position. He can also use his nails as short-range cutting weapons.
During the second stage of the Steel Ball Run, Johnny and Gyro traversed a Devil's Palm without knowing it and the Corpse's Left Arm fused with Johnny not noticing. Later against the Boom Boom Family, Johnny awakened his Stand Tusk, which enabled him to defeat Benjamin Boom Boom and L. A. Boom Boom.
Tusk ACT1 first appears to Johnny later during the second stage to inform him of the location of the Saint's Corpse's Eyes and briefly help him against Wired, spinning his toenails and allowing Johnny to deduce the true nature of the Steel Ball Run.
Manga Debut: SBR Chapter 43, Silent Way (4)
Mechanically, ACT2 possesses small, sturdy torso and arms, greater in proportion to its head. From its head hang two barrel-shaped objects. A barrel-like unit the size of its head is suspended at the base of a short, flat spine. Araki added some elements to make it unclear whether it's animal or machine, like a traditional Stand.
With an enhanced destructive power and new properties to its nail bullets, Tusk ACT2 is a direct upgrade to ACT1. It allows Johnny to fare better in combat, but limits the number of nails at his disposition.
Golden Rectangle Nails:
When Johnny activates Tusk, the fingernails now rotate around his fingers like axes. Thus, when he shoots the fingernails, they possess a drilling property, which dramatically increases the power of the shots. For instance, one shot is able to blast away a large zone on impact. On the downside, the nails regrow considerably slower, and as such, Johnny must save his nails or he will find himself out of ammunition.
In addition to the damage boost, the nail shots gain a new property: after they hit a target, they disappear and leave a black hole. These same holes created through the rotation can automatically chase after any target designated by Johnny in case he misses, leaving a dark trail behind them. When they manage to touch the enemy, the holes destroy him by tearing into vitals. The holes shrink and disappear after a while.
When Johnny shoots a fingernail with aureal rotation, the fingernail takes several minutes to grow back; however, Johnny discovers that by munching herbs or drinking tea, among others mint and chamomile, he can accelerate the growing process.
Like with Tusk ACT1, Johnny can keep the nails spinning around his fingers without actually firing them. He is mostly seen using this for mundane tasks like brushing his teeth, grating cheese and wrapping spaghetti around his fingers.
Because of their nature, Funny Valentine cannot use Dirty Deeds Done Dirt Cheap to send the holes into a parallel dimension. It is explained that the holes are by definition void and there isn't anything to send away.
Johnny unlocks Tusk ACT2 when Gyro teaches him about the Golden Rectangle. Aided by his newfound power, Johnny defeats Sandman; yet soon after, Hot Pants intervenes, knocks him out, and steal his Corpse Part except for a single vertebrae.
Manga Debut: SBR Chapter 59, A Dream of Gettysburg
Tusk ACT3 is the second evolution of Tusk, unlocked when Johnny witnesses Jesus counseling him and finds a renewed resolve in life.
Although it is distinctly more human in shape, its head is still embedded into its body. ACT3 bears sharp spikes growing from both the underside of each of the three toes of its triangular feet, and two from small, truncated, disc-shaped hands. On dark, spherical shoulders it bears the large, bold outline of a star; and from its upper lip to the rear of its head runs a tall, blade-like protrusion resembling a Mohawk.
Tusk ACT3 doesn't display any noticeable personality trait other than muttering its characteristic "Chumimin" sound.
Although functionally identical to Tusk ACT2, Tusk ACT3 involves Johnny directly exploiting the holes to reposition himself during a battle and increase his options.
Tusk ACT3 still possesses all the abilities and limitations of ACT2.
The hole created by the nail shot, specifically the infinitely small rotating point at the end of the hole, becomes a special space which, due to the infinite proportion of Johnny's spin, is also infinite and becomes a wormhole through space. A tailpiece theorizes the space as a boundary between dimensions. Johnny alone can enter that "location" and anything other than him will be cut. This ability is limited by how long the holes can persist in the world.
By moving the hole while his body is inside, Johnny is able to quickly reposition himself or key parts of him, such as his shooting hands, and attack from unexpected angles. Because the hole functions as a wormhole, anything sent into it will exit through the other end, although it will be severed. This includes enemy attacks.
Gyro deems this ability a new level of mastery over the Spin that even the Zeppeli Family hasn't accessed with their Steel Balls.
Manga Debut: SBR Chapter 85, Ball Breaker (3)
Tusk ACT4 is the highest evolution of Tusk, accessed only when Johnny uses the Super Spin.
ACT4 is of humanoid shape and broad or square build; of articulate legs, arms, hands and fingers. Its head is mounted on front of its chest, and from the bottom of its chest hangs to its ankles a vestment comprising strings of vertical ellipses. like Johnny, it wears a horseshoe on its forehead. The inside of its curtain-like body is hollow, and its face can move around like the Zaku's mono-eye.
Occasionally vocalizing ACT1's "chumimi~in", ACT4 punches while inciting Johnny's expression of the Kujo family's "ORA ORA ORA" Stand Cry.
The principle behind Tusk ACT4 derives from the use of the Super Spin, which requires Johnny to make his horse run in its "natural state". By doing so, the horse produces rotational energy in the form of the Golden Rectangle and by combining it with Tusk, Johnny is able to release infinite rotational energy. He can, however, shortcut the process as a last ditch effort, using a Steel Ball to temporarily galvanize his horse's movement.
Tusk ACT4 is thus one of the most powerful Stands in the series due to the infinite energy behind it, but is incredibly difficult to deploy as a trade-off.
Otherwise, Tusk ACT4 displays the physical abilities of a close-range Stand and is able to pummel Dirty Deeds Done Dirt Cheap.
Tusk ACT4 embodies the infinite energy and rotation of the Super Spin and is able to deploy it in various ways.
Following the principle of the Super Spin, the energy wielded and embodied by Tusk ACT4 is infinite, allowing a wide array of otherwise impossible feats. One of the first abilities displayed by Tusk ACT4 is to be able to break through the dimensional barrier of Love Train and enter the space in which Valentine hides. Moreover, Tusk ACT4 defies the laws of gravity and therefore can move slightly and probably still influence Diego during the stopped time. The damage caused by the rotation is stated to be probably infinite as well. Like with ACT2 and ACT3, the energy of the Spin can persist inside objects even if Johnny misses a nail shot, and can be redirected toward a target.
If ACT4 touches someone, it imbues the target with an infinite spinning motion. Not only does part of the body separate to spin, everything down to individual cells spin on themselves, greatly distorting the shape of the victim. Eventually the targets are disintegrated by the rotation and according to Diego, sent to another dimension. The Spin goes on forever and never leaves the person or their Stand, forcing them to return to the place where they were hit or its equivalent in each parallel dimension, thus Funny Valentine was not able to escape it despite switching dimensions and bodies and always returned to the underground location in which he was hit. If someone uses a tool, like a carriage, to get away from the location, the Spin will imbue itself into the tool and destroy it, forcing the target back into their location. The rotation won't end unless Johnny shoots the target with a similar rotation moving the other way, resulting in them cancelling each other out.
Tusk ACT4 can also apply the Spin's energy in a more similar fashion to its previous forms and open a large space where there was none, as was shown in Johnny's battle with Diego Brando during which he opens a hole through the ground and enters the sewers with his horse.
The Spin is also transferable between objects, as the Diego Brando from another universe cut his leg off and threw it to Johnny, transferring the infinite rotation to its user. Another example is when Funny Valentine went into a passing car trying to escape from Tusk; the infinite rotation destroyed the car near-instantaneously, and returned back to Valentine.
Johnny unlocks Tusk's fourth and final form after receiving Gyro's fifth lesson.
- Johnny can use his Spinning nails to grate cheese, wind spaghetti, and brush his teeth as though with an electric toothbrush.
- According to himself and Hot Pants, Johnny only possesses Tusk when he carries a Corpse Part; however, he is able to use Tusk even when the Corpse is fully reassembled
- Occasionally, Tusk's name is written with the kanji "爪" (Tsume, lit. "Nail"), rather than its traditional "牙" (Kiba), which is a reference to Tusk's fingernail shooting ability.
- Araki specifically created Tusk ACT1 with being a mascot to Part 7 in mind.
- Due to copyright laws, Tusk's name in the Italian release of Steel Ball Run is written as "Tasuku", which is the japanese pronunciation of the stand's name.
- ↑ 
- ↑ 2.0 2.1 SBR Chapter 27
- ↑ 3.0 3.1 3.2 3.3 JOJOVELLER: STANDS - Comments by Hirohiko Araki
- ↑ 4.0 4.1 4.2 SBR Chapter 19
- ↑ 5.0 5.1 5.2 5.3 SBR Chapter 26
- ↑ SBR Chapter 23
- ↑ 7.0 7.1 7.2 SBR Chapter 44
- ↑ 8.0 8.1 SBR Chapter 45: The Land of Promises: Sugar Mountain (1) p.9
- ↑ SBR Chapter 45
- ↑ SBR Chapter 78
- ↑ SBR Chapter 58
- ↑ SBR Volume 22, tailpiece, SBR Chapter 86
- ↑ 13.0 13.1 SBR Chapter 59
- ↑ SBR Chapter 86
- ↑ SBR Chapter 92
- ↑ SBR Volume 22, tailpiece, SBR Chapter 87
- ↑ SBR Chapter 94
- ↑ SBR Chapter 93
- ↑ SBR Chapter 95
- ↑ SBR Chapter 86
- ↑ SBR Chapter 87
- ↑ SBR Chapter 92
- ↑ SBR Chapter 94: The World of the Stars and Stripes pp.19-20