Had a small army of dinosaurs I was walking to a cave on ragnorok. 5 raptors 8 dilo, and 2 Allosaurus. The allo and raptors averaged around level 50, the dilos were between 180 and 260 (happened to tame a high level breeding pair). I was mounted on the highest level allo so I had pack leader bonus. Cave was on the center north side, I poked my head in once and found it was really dark, only went in long enough to confirm that it was indeed a proper dungeon cave and not just some random hole in the ground. Before returning to fetch my army.
Found a big carnivore dinosaur on the way there that I never saw before. I did not recognize the name but it was only level 25, so I figured my army of smaller dionos would tear it to shreds in seconds just like it did everything big on the way there.
It was a Acrocanthosaurus. it has special abilities. First it does extra damage to anything smaller than it. My biggest dino, the Allosaurus I was riding, was half it's size. Second it goes into shield mode where it takes reduced damage and if hit enough while in shield mode it enrages and gets doubled attack speed. I did not know any of this, I simply expected it to be about the strength of a T-Rex I had taken out easily earlier in the march.
It destroyed me. 3 of the level 150+ dilos and one of the raptors died in a single attack, but immediately after that I beleive it went into shield mode because it stopped attacking as much, which I thought was because it was bleeding from my Allosaurus's special attack. Then after a second it roared and got it's enrage. Next attack the lower level allosaurus died along with most of the remaining dilos, next the remaining raptors were toast, then the highest level dilo the lv 260. then after a few back and fourth hits my mounted allosaurus died, at which point I hit the ground running but eventually turned into it firing my gun when it became clear I couldn't outrun it on foot, and I was hoping to get inside it's attack range, didn't work.
Came back a little later on my griffon to collect my corpse and look up what that was that killed me, griffon baited it into falling off a cliff so I could get my stuff. Now it's stomping around the beach giving the giant dinosaur turtles a hard time.
ARK