Sheldon

"Hello, hello! What kind of weapon are you in the market for?"

- When the player enters Ammo Knights

Sheldon is the horseshoe crab who owns Ammo Knights, a weapons store in Inkopolis.

Appearance
Sheldon has brown eyes and buck teeth, and because he is a horseshoe crab, his helmet is the shell of that species of chelicerate. Sheldon wears a military jacket and boots, as well as a red scarf and a red belt. Sheldon also has what appears to be brass binoculars that he seems to use as glasses. In Splatoon 2, he wears an apron with badges that look like Cub Scout group badges.

Personality and traits
Sheldon is a military fanatic from a well-respected family who is fascinated with his weapons. When talking to Sheldon inside his shop, if the player has unlocked any new weapons, he enthusiastically explains all about them in great detail. He has developed nearsightedness due to staying up late every night tinkering with weapons and small parts, causing him to be rejected from the military for his extremely poor eyesight. Undaunted, he decided to start a business selling weapons out of his own home, and Booyah Base was eventually built on the same land upon which that home stood. However, it was not Sheldon but his grandfather, Ammoses Shellendorf, who owned the land. In, he seems to have improved his skills in creating weapons as he is now able to create new versions of the Hero weapons as well as upgrade them with a machine he made as well. When the Hero Replicas are available to be purchased, instead of saying he could not replicate the technology like in the first game, he says that the weapon was not able to be mass-produced by "the guys at the factory".

[[Media:Shop - Ammo Knights.oga|Sheldon's version]] of DJ Lee Fish's song Lookin' Fresh is more distant, showing his separation from the others as a weapons dealer. It also has static and other sounds reminiscent of a military radio, as a reference to his obsession with the military.

Major appearances
In Chapter 46, Sheldon appears in Ammo Knights in Inkopolis Square, giving Specs his repaired Octobrush. A few moments later, he nominates himself as a judge for the Turf War against Team Blue and Team Glasses at Snapper Canal. In the nature of his attention to detail, he explains the history of Snapper Canal, in which Team Blue has no interest in. He notices Team Blue's strength on the field, specifically Goggles, and later asks Goggles to help him uncover the mysterious treasure that his grandfather left behind.

Having recruited Goggles, Sheldon states that some of the weapons that are used in Turf Wars today were made on Mount Nantai, such as the Hero Shot, Dynamo Roller, and Aerospray. The treasure eventually turns out to be a weapon that resembles the Splattershot but is far more powerful. There is also a note inside, and Sheldon is moved to tears reading it. He insists that he will use the weapon for research and not for Turf Wars.

Minor appearances
Sheldon debuts with a brief appearance in Volume 1. He is seen frustrated at Team Blue's silliness when Goggles steals weapons from his shop and wears them. Sheldon later reappears in Volume 12, where he is seen driving Marie's truck in Octo Canyon. Sheldon also introduces two new agents, Agent 4.5 and Agent 4.25, who are revealed as Skull and Vintage.

In the bonus chapter of Volume 12, Grandpappy's Note, Sheldon knocks over a stack of boxes in Ammo Knights, and finds a note from his grandfather. He decides that he wants to go and look for it, and starts to think about who he should take along. He eventually decides on Goggles, and leads into where Chapter 46 left off.

Trivia

 * Sheldon's name plays on the word shell. This can refer to both an ammunition shell and the shells of horseshoe crabs.
 * Ammoses Shellendorf, Sheldon's grandfather (or 'Grandpappy' as he calls him in the game), was part of the original Squidbeak Splatoon, led by Cap'n Cuttlefish.
 * Sheldon appears to be missing eight eyes compared to real horseshoe crabs. It is possible that he is wearing something over his shell which would hide the extra eyes.
 * One of Callie and Marie's conversations in Octo Canyon ask whether if Sheldon is part of the New Squidbeak Splatoon or not. Marie says that he was invited, but he says that the "tech team" has to keep its distance from the front lines; neither Callie nor Marie know what this means.
 * Sheldon is the third-generation owner of Ammo Knights.
 * Ammoses Shellendorf was the first owner of Ammo Knights with the second probably being Sheldon's parents.
 * Sheldon is the director of the Turf Wars association.
 * A time limit was put in place for speeches due to how long his speeches took during assemblies.
 * Sheldon's design seems to be inspired by the Boy Scouts of America, as seen in the khaki shirt and neckerchief in his design in and the diamond arrangement of badges in, which have the same colors and arrangement as those of a Cub Scout.
 * Sheldon was neutral for the Chaos vs. Order Splatfest, as he cares little about the fate of Inkopolis as long as he can continue building ink-based weaponry.
 * A crab similar to Sheldon can be seen in Mahi-Mahi Resort.
 * According to The Art of Splatoon 2, the Splattershot badge on his apron was made by Annie.