If someone it disapproves of attempts to wield it, spikes protrude from the handle in order to force them to release their grasp, at which point Samehada will make efforts to return to its chosen owner. Being capable of conscious thought, Samehada chooses its own user, an exclusive process that has often resulted in it being thought of as notoriously picky. However, it has shown displeasure towards fire-natured chakra, stating that - according to B - it's far too hot. It apparently greatly enjoys Killer B's chakra since, according to Kisame, it tastes like octopus.
Samehada is unique for being a sentient weapon that gains nourishment from the chakra of others and as such, the blade is at its happiest when engorged with chakra that possesses both a distinctive and pleasant flavour. Samehada refusing to let Kisame wield itself. Keeping Samehada wrapped in bandages apparently helps to inhibit this growth to a certain extent. Samehada grows larger in proportion to the amount of chakra it absorbs, causing its scales to become so long that they ultimately resemble shark fins and its mouth, located at the tip of the blade, to become even more pronounced. Though mostly wrapped in bandages, Samehada's construction is atypical in that its actual blade is comprised from a series of downward facing scales running along the entirety of its length until its hilt, at the base of which is a small skull.