How does Emily Dickinson use imagery in A Narrow Fellow in the Grass?

As the poem proceeds, the imagery continues to paint a picture of the snake as a harmless creature, one of "nature's people," with whom the speaker is well-acquainted. The snake is again called a "fellow" in the final stanza, but this time, the context is different. The speaker is revealing his fear of the snake. Meeting this creature, this "narrow fellow," either "attended or alone" causes "tighter breathing." It causes the speaker to feel "zero at the bone," or to be chilled to the bone. The final stanza describes an irrational fear.