I firmly believe that was Sarah Palmer at the end...but was she taking on BOB or Laura before the credits?
I think Laura and BOB orbs are separate from the creature eggs. If that was Sarah Palmer maybe the creature that crawled into her mouth gave her her connection to the lodge worlds. She was one of few people who could see BOB, and she had dreams/visions of other occurences too. Also I think in the finale she conveys a message from the red room to Major Briggs.
I'm rather sure the "moth frog" is Bob's embryonic form, seeking out its/his first host. It's not The Experiment - that's the goddess Babalon who spewed out the creamed corn stream with all the egg/orbs.