Cosmo can be found in the green zone, I've had the best luck near the fertile lake. Creature finder mods help, as these things are tiny. To tame, approach it with chitin in your inventory. Wait until it starts to glow, then passively feed it chitin or plant species z seeds. (Z seeds are the best). Once tamed, you can put it on your shoulder and turn it into an item. To swing, equip cosmo item and enjoy. Webs recharge automatically, and from my experience capacity can not be leveled but can increase the higher level the tame. (Level 25 was about 20 capacity, and level 100 was about 40)

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