Creature From the Black Lagoon is a combination of the horror and science fiction movie genres.
A horror movie's intent is to...
...elicit a negative emotional reaction from viewers by playing on the audience's most primal fears.
In essence, these movies strive to create a "bump in the night" experience, a purely terrifying moment often experienced as children. These films capitalize on...
...viewer's nightmares, hidden worst fears, revulsions and terror of the unknown.
The horror genre capitalizes also on the presence of evil. While the supernatural may be involved in horror movies, horror movies do not include all movies involving the supernatural.
The science fiction film genre presents a story where...
...the plot depends on the laws of mathematics and the physical sciences, or on the use of technology...
What adds to the fear involved in this kind of film is that the story presented is credible in some way, allowing the possibility that what occurs in the film might plausibly occur under certain circumstances in real life. Whereas the science fiction of today is somewhat more advanced than in 1954, some aspects still remain, such as "encounters with other life forms," and the "creature" (though called a monster) was definitely a "form of life" mankind had never seen before and did not know how to fight.
Structurally, "Creature" was a B-movie. This basically meant that it had a lower budget (reduced costs) and did not contain well-known actors. Because of these two elements...
...these films usually drew heavily on their genres, yielding formulaic narratives and styles.
In "Creature," there were several aspects of the film that were "formula-based" in terms of horror movie making. The "formula" aspect of the movie is found with the inclusion of two of several "tropes:" the "scientist-protagonist" and the "Beauty and the Beast" theme as well as...
...the ignored girlfriend [and] the primeval man/beast...These conventions serve as mainstays for Creature’s plot.
Other characteristics the film shares (in terms of the creature) with similar movies (e.g., King Kong) is "a hatred of men and a love of women" and "susceptibility to drugging."
Perhaps the most surprising aspect of "Creature" is that it was a much bigger success than had been anticipated. Film studios were making movies in a post-atomic bomb era. The idea of unnatural creatures living on the earth and threatening mankind was a standard issue kind of film at the time. However, "Creature" somehow caught the imagination of the generation (and generations to come). The underwater filming was impressive to audiences; the musical score was produced (only in part by the well-known Henry Mancini), with sounds that became associated with the "Gill-man."
Perhaps it started out as a B-movie, capitalizing on formulaic elements, but "Creature" became a film classic that is still enjoyed and praised by viewers of all ages even today.
I can tell you something about this place. The boys around here call it ‘The Black Lagoon’; a paradise. Only they say nobody has ever come back to prove it.