This is a must have if you're looking into fishing. Some will recommend a fishing pen which is good depending on where you want to build.
We actually hopped on my metal raft, placed a chair and the pachyrhino on top, I would go scout the area below us for fish and dangerous Dinos like Sarcos, Megalodons, Baronyx or anything that can give us a tough time while kiting the fish towards the boat, have your friend throw down the bait, throw red mist (R32 on PS4) aggro all coels in the area and swim circles around the bait.
If you want yo fish, tame or have a way to keep smaller Dinos calm to help for safe gathering or working.
While fishing, are you sick of all the fish being scattered? If you bring this dino near the shore or on a boat where fish are near by and use the aggro mist, it will aggro the fish to come right to you in a big crowd!
Their “nice” gas might be the gas form of soothing balm. Also it’s effect is to reduce the stamina of everything caught in the “soothing” cloud. Also if it lays eggs why not make its crap soothing balm?