pilot blacksnake vs black rat snake

pilot blacksnake and black rat snake both are nouns.

Word	Noun	Adjective	Verb	Adverb
pilot blacksnake	Yes	No	No	No
black rat snake	Yes	No	No	No

As nouns, pilot blacksnake and black rat snake are synonyms defined as:

pilot blacksnake and black rat snake: large harmless shiny black North American snake

Other synonyms of pilot blacksnake include blacksnake, Elaphe obsoleta, mountain blacksnake.

pilot blacksnake (noun)	black rat snake (noun)
large harmless shiny black North American snake	large harmless shiny black North American snake