'Twas brillig, and the slithy toves Did gyre and gimble in the wabe; All mimsy were the borogoves, And the mome raths outgrabe. (1-4)
This difficult-to-comprehend initial stanza sets the tone for the "natural" world in which this poem takes place. Carroll seems to deliberately pick words that will give the reader a sense of the natural world, even though there may be no direct evidence for it. (Wabe sounds like wave, toves sounds like groves, as does borogoves, mimsy sounds a bit like pansy.) And even though these words might correspond to something that isn't related to these comparisons (for instance, mimsy is an adjective, not a flower), the sounds still hold, and we still get the sense that we're outside, in a "natural" setting. This is sound play at its finest. Carroll is doing two things at once here. Even though his made-up words don't correspond to anything natural, we get a natural feel from them anyway.
The jaws that bite, the claws that catch! (6)
This one line, in terms of man and the natural world, sums up the entire stanza because it contains beastly body parts. We tend to think of nature in terms of differences. How much we're not like a shark, a tiger, or a manatee. This line highlights those differences, because while we have jaws that do in fact bite, we don't use them, say, as predators. And we certainly don't have claws. At any rate, this sort of "parts description" of the Jabberwock de-humanizes it, and puts man in opposition to the non-human (i.e., "natural") world.
So rested he by the Tumtum tree, (11)
This is directly in opposition to the "nature will kill us" stance of the quote above. It's interesting how the natural world fluctuates between mauling us and providing us with comfort, as the Tumtum tree does here. It's a peaceful line right before the chaos – our hero is tired, and so in an idyllic moment, he stops and rests beneath a tree. We can picture the tree arching above him, providing shade and a kind of shelter. This is the "mother" part of Mother Nature, perhaps.