DO NOT believe that this reduces weight on its inventory. As of today AUG 2020 I tested stacks of meats and berries etc, IT DOESNT. But instead it increases spoil timer of foods, meats and berries on its inventory. ⬆️ to prevent ppl from false informations!
So to who ever wants to know how to get these on mobile ( it's quite difficult) first you have to find and kill them in a dungeon, defeat the dungeon and the revive them using their implant and a revival platform then tame as you normally would. Have fun with your new furry friend