How we cite our quotes: (Chapter.Paragraph)
Quote #4
The monster smiled. It was a ghastly sight. If I must force my way in, it said, I will do so happily. (5.16)
By not telling us exactly what the monster's smile looks like, Ness is letting us imagine it for ourselves, which is often scarier than anything anyone could describe (or, in this case, draw).
Quote #5
Even though it walked and talked, even though it was bigger than his house and could swallow him in one bite, the monster was still, at the end of the day, just a yew tree. Conor could even see more berries growing from the branches at its elbows. (7.35)
The berries on the monster's elbows remind us of the berries Conor found on his bedroom floor after its first appearance. He'll later sleep among them when the monster makes a nest of its arms. Ness is subtly weaving a piece of characterization through the book for those of us who are paying close enough attention.