I believe that they killed their own offsprings (babies inklings and babies octorians and other babies) since they’re still resembles or look like a squid and octopus. But it’s still possible that they could kill and mutilated an adult inklings and octorians. “Why there’s no news about murders?” Maybe because it’s already a normal stuff there so they’re not really surprised
Oh yeah it also means they’re cannibals
Well who knows?
this is just a little theory that probably wrong lol. As you see on the title, I’m not really into Splatoon xd