If 7 want alot of chiten kill matisis no matter what u use youll usually get at least a hundred. If you use a megatherium u got almost 1000 with a tame. U got a breed one your looking at 1500 each mantis
Mid game strategy: Bring any of your mobile hard-hitting Tames with decent weight, kill any Karkinos, but make sure to harvest the corpse with a chainsaw. Voila, you've not only gotten thousands of Chitin, but also thousands of Organic Polymer in likely under 15 minutes. With a x3 harvest server, I could easily net ~1k Chitin per crab with a prim chainsaw.