Answer:
The final stanza develops the theme that things that are admirable may still be terrifying when The speaker calls the snake a fellow, but his reaction upon seeing the snake shows he is shaken up.
Step-by-step explanation:
The poem "A Narrow Fellow in the Grass" by Emily Dickinson gives a description of the snake as an animal with a lot of impressive characteristics, and that could even be admired, idea that collapses in the last stanza where the speaker demonstrates that he is in fact terrified by the animal with the words "tighter breathing " and "Zero at the Bone".