This new sub weapon is the Autobomb. As its name implies, once thrown, it will automatically start walking toward a nearby opponent. When it approaches the opponent, it stops and goes KERSPLAT!
— Squid Research Lab
Source: Splatoon’s Tumblr.
…Wanna play? Buy a Switch.
And if you’ve already got yours, click on Splatoon 2 for everything you need to know about the game. 😀