gopher snake vs bull snake

gopher snake and bull snake both are nouns.

Word	Noun	Adjective	Verb	Adverb
gopher snake	Yes	No	No	No
bull snake	Yes	No	No	No

As nouns, bull snake is a hypernym of gopher snake; that is, bull snake is a word with a broader meaning than gopher snake:

gopher snake: bull snake of western North America that invades rodent burrows
bull snake: any of several large harmless rodent-eating North American burrowing snakes

Other hypernyms of gopher snake include bull-snake.

gopher snake (noun)	bull snake (noun)
large dark-blue nonvenomous snake that invades burrows; found in southern North America and Mexico	any of several large harmless rodent-eating North American burrowing snakes
bull snake of western North America that invades rodent burrows