As an early/mid-game player, I found one of these wandering around my base. Seemed like it was stalking me. Every time I tried to leave my base to gather resources, it got upset. Luckily, I had a raft in which I turned into a small ship. So, I hopped in my raft (fortunately I’m building on a beach) and shot it with a crossbow from a distance. My goal was to piss it off enough to swim out to get me, and lead it into a pack of megalodons. Lo and behold, I killed it with enough crossbow hits eventually as it swam.