>>11333086
There was a movie about a kid whose village got hit by an earthquake and after that a bunch of giant ox things arrived there, clearly a metaphor for his trauma
So basically you make the giant monster a huge looming allegory rather than an immediate threat, that's probably the most obvious way
With a giantess you could make it a giant girl's heel perpetually on the protagonist's back or something making it hard for them to walk
>>11333090
>Giantess is a sea monster goddess who is threatening your town but one day communicates with you personally and it's your responsibility to try and stop her somehow
But then you actually end up giving in to her seduction, helping her and betraying humanity, leaving everyone to suffer under her reign, and the story is focused on the gradual degradation of your self and complete submission to her (though this wouldn't be strictly horror anymore)