"Man and the Natural World" might be the most interesting theme in the whole poem, because it's the one theme in which we can bring in the goofy language. How, you ask? Well, the "natural world" that Carroll creates certainly doesn't seem to have anything to do with the "natural world" that we inhabit, yet there are many similarities between the world of the Jubjub bird and the world of the ordinary owl. Carroll's positioning of hero vs. beast is essentially the age-old story of Man vs. Nature. While the theme "Good vs. Evil" also figures into "Jabberwocky," the Evil in this case is basically Stuff We Are Afraid Of In the Woods. Even the first peaceful stanza is full of unknowable, strange creatures doing unknowable, strange things. And they get significantly less peaceful when they return in the second stanza, because not all the evil has been banished.
"Jabberwocky" is an example of man's desire to conquer nature.
The fantastic setting of the poem exploits both our fear of, and curiosity about, the unknown natural world.