Now that these are rideable, they are amazing super-low level tames if you can find one that wants Tintoberries or something to that effect. Not only do they gather Thatch and Wood from trees, but they also harvest bushes for Fiber and berries, plus harvest bodies of all types. They essentially make taming Therizinos pointless.
Feeding it what you want it to gather has NO EFFECT on its father rates. These are determined by the additional level granted every level to increase your moschops' gathering efficiency of your chosen resource.
Best for if you need fast polymer for crafting. I have used this countless times to make all the industrial equipment. But only level up health and weight and put the gathering levels into polymer. Mines at 530% and I get 50 polymer per penguin. ðŸ‘