Sardinium

Sardinium is an item in Splatoon 2's Octo Canyon used to upgrade weapons at the Ammo Knights Enhancifier.

One Sardinium can be found in each Octo Canyon mission. Standard missions have a hidden Sardinium that the player must find, while each boss mission's Sardinium appears in front of the Zapfish after the boss is defeated. There is also one hidden Sardinium in each sector of Octo Valley.

Collecting a Sardinium that has already been found once before will found give the player 5 Power Eggs instead.

Trivia

 * Sardinium pieces resemble sardine, hence the name.