mamba vs black mamba

mamba and black mamba both are nouns.

Word	Noun	Adjective	Verb	Adverb
mamba	Yes	No	No	No
black mamba	Yes	No	No	No

As nouns, black mamba is a hyponym of mamba; that is, black mamba is a word with a more specific, narrower meaning than mamba:

mamba: arboreal snake of central and southern Africa whose bite is often fatal
black mamba: a highly venomous southern African mamba dreaded because of its quickness and readiness to bite

Other hyponyms of mamba include Dendroaspis augusticeps.

mamba (noun)	black mamba (noun)
arboreal snake of central and southern Africa whose bite is often fatal	a highly venomous southern African mamba dreaded because of its quickness and readiness to bite