There is crystal cave on Ragnarok around 12,23ish where you can trap the mosa, I use a ichy to trap them as they are small enuf to get in the sallow area but the mosa can’t so they get stuck👍... hope this helps
JUST TAME A SQUID GRAB THE MOSA,DISMOUNT THE SQUID.....and put the Squid on passive I will no let go of the mosa.AND THEN THE SQUID WILL BE DOING TORPOR AND ALSO YOU CAN HARPOON IT OUT AND TAAAAAAAAAAMMMMMMMMMMMMMME!!!!
Center tip: as they have added the mosa to the center I've found the easiest way to knock one out is find one close to the bubbles get its Agro and swim in the bubble the mosa will get stuck and it can't hit you. Also this gives you unlimited oxygen and sanctuary from being attacked by anything else. ðŸ¤˜ðŸ¼
More over on the dlc you would have pocket of space where you could create tools and have a breath of air there would be creatures that could give you water similar to oil bugs. With vents that would go and shove you upwards. The new creature would be a thing that would set up deep sea areas and required food to be dragged towards it similar to otters they would speed as super sonic speed and inflict a deprevention debuff that starves you of oxygen. It would be able to morph into the ocean floor or the top to hide itself