Use a Mosa to tame this beast. Let the Mosa get grabbed wait a couple seconds get off feed it black pearls. Have your mosa on follow lowest, swim a bit away from the Tuso after feeding it, when the Tuso lets go the Mosa will swim to you. Repeat until Tuso it tamed. Super easy!
If you want to tame a tuso (you will at some point) bring a high health turtle and at least 100 black pearls (silica pearls don’t work) let the tuso grab the turt and go to the tusos mouth and feed it the pearls.
1: The best place to encounter tuso is 90-91 lat and cover all longitude from red ob to the end of herb Island.
2: Don't solo search, make a party and cover full bottom of the map.
3: Don't search in shallow water and surface, go for mid and deep sea.
4: They need to grab your tame then only can they be tamed.(Take Carbonemys with health and speed pumped)
5: They take 50 black pearls per serving.
6: They only agro in deep sea.
7: Last and the most important, the server must be brutal or their chance of spawning is not that much. Put server to brutal and for one day atleast go killingspree in ocean to open spawn spots for tuso.
You need two people, one for feeding the black pearls and the other to feed the turtle that is in the grasp of the Tusoteuthis, with sweet vegetable cake for the health and to feed it stimulates berries as well