Who knows if they were not affrighted by the arrival of this formidable, winged monster, which they could not match either in might or speed.
McLoughlin wanted Jason to be more of a "formidable, unstoppable monster."
However, formidable monsters are lurking along their path.
I have fought with one of the most formidable monsters of the river.
Kessell must be mighty indeed if he held this formidable monster under his control!
"Too many," Ivan muttered, and indeed, no fewer than twenty formidable monsters surrounded their helpless friends.
Highly abnormal things are occurring here and now, for example, in the metro, where Valérian faces a formidable monster of fire.
That would suffice to make a formidable monster.
The more formidable monsters were laying about them with similar glee, reveling in an orgy of slaughter.
The dragon was no longer little and cute; he had in the intervening years become a formidable middle-sized monster.