Final answer:
Goodman Brown encounters a mysterious man who is suggested to represent the devil, marked by a staff that appears as a living serpent.
Step-by-step explanation:
The man mentioned in the student's question appears to be a character from Nathaniel Hawthorne's short story, Young Goodman Brown. This character is met by Goodman Brown in the forest as he sets out on an errand that is not explicitly named but is understood to be of a dubious moral nature. The character encountered by Goodman Brown, often interpreted as the devil or his emissary due to the serpentine staff he carries, is described as being of a similar rank as Goodman Brown and bearing a considerable resemblance to him. Particularly noteworthy is the descriptive detail provided about the mysterious man's staff, which resembles a great black snake. The staff appears to twist and wriggle as if it were a living serpent, a strong symbol often associated with evil and deceit.