even if one says

fabulous monster

a monster / a mysterious figure

terrific, wonderful, splendid, grand, magnificent / (obsolete) extreme, terrible

marvelous, wonderful, splendid, magnificent

to say, to tell somebody / to call, to name, to give a name / to cry, to call, to make a noise (such as an animal)

past tense and perfective aspect of 言う (iu, yū) [godan]

nonetheless, although, be that as it may

in other words; what I (you, etc.) mean is

to startle; to surprise; to astonish