without any of the added implications of frost’s books, my interpretation of the “frog moth” from part 8 was that it represented essentially a flesh world counterpart to BOB.

to me part 8′s extended atomic explosion sequence immediately evoked 2001: A Space Oddysey’s famous stargate sequence, and I think frost and lynch were turning kubrick on its head with BOB’s origins in this episode. while in the universe of 2001, it’s interdimensional alien benefactors who are responsible for human violence and ultimately the creation of the atom bomb, the monolith somehow providing the early ape with the idea to commit murder with a bone. but in part 8, the opposite seems to be true of the world of twin peaks; in finalising the creation of its ultimate weapon in 1945, humanity also allows the creation of the interdimensional spirit of human violence, and from the spawn of judy, BOB is born.

the vomiting child in part 11 i think is another, smaller-scale example of this. a child accidentally comes into possession of a gun through parental negligence, fires it, and chaos ensues. this vomiting child is another spirit of evil born from this chaos; a representation of violence born by the use of manmade weapons.

and if BOB is the “spiritual” consequence of the white sands nuclear test who “enters” people through possession, the frog moth is then the “physical” consequence of the explosion. crawling from an egg in the irradiated sands with a multitude of mismatched limbs which barely seem able to function the way they should, we are given the impression of something mutated; literally created by the radiation resulting from the blast. and an animal that literally, physically enters the bodies of humans by crawling in through their open mouths.