Octoballer
From Inkipedia, the Splatoon wiki
Octoballers are Octarians in Splatoon 2 Octoballers are fired from canons and will roll on the ground, splating anything that gets in the way. They can be destroyed by attacking the Octotrooper. Some Octoballers will not leave behind a trail of ink. The giant Octoballers move slower, but they can only be destroyed with ink canons