In mobile, if you ever got your precious dino get stinged by these, you can either equip your strongest melee weapon and kill the cnidaria or quickly jump back on land and go to your inventory -> your charater info -> look into the stat section then find and press the tame button (it will bring up the list of all your tamed)then select the name of your endangered dino and chose request, it will take a short amount of time(about 20 seconds) for the request to be done then after it done, your dino will be next to you

NOTE: for land dino, you must be on land in order to request, for sea dino you can either request while in water or do it on land then jump back in

I had save my megalodon from cindaria 2 time and my rex 1 time now

Up if found useful