Sind became much larger than an average child due to the experiments done on him at Punk Hazard. His head is rather big and not very proportionate to his body. He has blonde hair (blue in the manga), that is unkempt and goes over his ears, he also has blonde colored eyebrows (blue in the manga). He wore a sleeveless shirt with shorts, until Kin'emon gave all the children jackets. His jacket was light colored, with a dark colored hood, and fur at the end of the sleeves.
In a photograph held by his father, he can been seen at his normal size, which was that of an average child.
When deprived of the drug NHC10, Sind became very aggressive, brutally punching Luffy into part of the building. Otherwise, he is a normal timid child, as he was scared of Kin'emon's severed head.
When not under the effects of the drug, Sind is a boy with high hopes, as he had reassured Mocha near the beginning of being taken from his home, believing that they would be better soon and be able to go home quickly. He has also stated that he wanted to be a pirate at the age of 20, getting very excited for it.
Abilities and Powers
At some point, he was taken from his father after being told he was sick and would be made healthy again. He was taken to Punk Hazard where he stayed until the Straw Hats' arrival.
Punk Hazard Arc
When the Straw Hats arrived at Punk Hazard, he begged the pirates along with the other children to save them. After being freed, he succumbed to the withdrawal symptoms of NHC10, which he and the other children were fed regularly in candy form. Eventually, Sind became very aggressive, punching Luffy through some pipes. Sind, along with the other children went on a rampage until Usopp managed to knock the children out using the sleeping gas, leaving the Straw Hats no choice but to chain the children up for their own safety.
Sind was then seen breaking out of their chains attacking Nami and Usopp due to the effects of NHC10 and then going back to Caesar for more "candy" with the other children.
Later, when the Straw Hats had infiltrated Caesar's lab, Mocha and Chopper kept the wild kids from going to the Biscuits Room. When Sind and the kids finally advanced, they chased Mocha, who had taken all the candy, and attacked Chopper in his Monster Point. They soon reached the Biscuits Room and overrun Robin's Mil Fleur technique in their run. Mocha ran on and the kids follow soon after, while being chased by Robin, Nami and Chopper. They eventually cornered Mocha and attacked her, trying to take the candy from her hands. However, Mocha ate the whole batch and Sind, among others, got mad and attacked her. Soon after, the Marines arrived and subdued Sind and the other kids, for Chopper to sedate them. Sind was quickly put to sleep.
After he woke up from his sleep, he ran with Nami, Robin, Sanji, the G-5 Marines and the other children to the exit of the Building R. Soon after Law cut the entire laboratory, the gas, Shinokuni started to seep in which scared him along with the other kids. At the same time, the group joined up with Zoro and Tashigi who came running towards them and continued to run to the exit.
The group eventually reached the exit and joined up with Luffy and his group. Soon after that, Law and Smoker reached the exit with a cart that Law meant to use for escaping the laboratory. When the rest of the children, Straw Hat pirates, Caesar’s subordinates and G-5 Marines reached the exit, the survivors started escaping from the crumbling laboratory.
While everyone was escaping through the tunnel, they heard an explosion coming from Building D. The explosion caused the corridor to collapse. Law noted that if the tunnel is part of the mountain that if it collapses they will be buried alive. But they eventually reached the exit safely due to the actions of Zoro and Luffy. Upon breaking through the exit and reaching the outside world, Sind noticed the Franky Shogun along with the other kids and the G-5 Marines. He reacted to it just like Luffy, Usopp, and Chopper (except for the female children).
After Caesar Clown, Buffalo and Baby 5 were captured, Sind was seen along with the other kids after having the medicine in their bodies removed by Law. They state their concern about Mocha's well being, but Chopper assures them of her safety by saying she will wake up soon. Then, they ask where Nami is and ask if she will take her home. Tashigi enters the room however, stating that the marines will take care of them now, much to their disliking. Soon after, Sind and the others are seen gathering around the food Sanji made with bowls in their hand and drooling mouths. Not long after that, all the survivors start a party together.
When the party came to an end, Sind and the other kids were escorted by the G-5 Marines on to the tanker. While the Straw Hat pirates were preparing to leave as well, Nami said to Chopper that Vegapunk was going to help cure the kids from the effects of the candy. As they began to leave, the Marines put up Marine banners to prevent Sind and the others from seeing the Straw Hat pirates while saying that the marines are justice and pirates are scum. Sind and the other kids still wanted to see the Straw Hat pirates and told the Marines to move. The Marines responded to them by pointing their rifles at them saying that only bad kids want to see pirates.
However the kids insisted that the Straw Hat pirates tried to save them even though they knew nothing about them. Sind also said that even though nobody ever came to the island, they did come. However, the Marines kept insisting that pirates are always evil and that they are justice. Tashigi then interrupts them and said they are a disgrace. The G-5 Marines told her that if they did not bad mouth the pirates, they would come to respect them. Finally the Marines gave in and let Sind and the other kids say their goodbyes. They also stated that they would become pirates too when they grow up, regardless of the disapproval of the G-5 Marines gave them.
While traveling with the G-5 Marines, Tashigi informed the children that they will see Dr. Vegapunk in a few days.