salamander vs mythical monster

salamander and mythical monster both are nouns.

Word	Noun	Adjective	Verb	Adverb
salamander	Yes	No	No	No
mythical monster	Yes	No	No	No

As nouns, mythical monster is a hypernym of salamander; that is, mythical monster is a word with a broader meaning than salamander:

Other hypernyms of salamander include mythical creature.

salamander (noun)	mythical monster (noun)
any of various typically terrestrial amphibians that resemble lizards and that return to water only to breed	a monster renowned in folklore and myth
fire iron consisting of a metal rod with a handle; used to stir a fire
reptilian creature supposed to live in fire