When I was still a noob, I was walking around to see a Thera across from me behind a very shallow river. I rode my beloved para that I had many adventures with, (in my mind) the biggest being getting stuck in a rainforest for a few days because I got so distracted trying to tame a pterodon, but learned I needed narcotics. We got attacked my a raptor and found our way out. (She killed the raptor, it was low level) and so, we walked across the river. I thought, "oh it's probably neutral because a territorial Dino would protect itself." ..... Oh dear god was I wrong. I got too close, and the Thera proceeded to chase us as I ran home. Panic made me stupid, because that just led it to our side of the river. It killed my beloved and I ran as fast as I could. It killed me, I respawned at my base, came back for the para saddle and my items, and every time to this day I see a Thera in that area and never dare to set foot there.