Where does “terato-” come from?

terato- (English) comes from Ancient Greek τέρας, from Proto-Indo-European kʷer- — to do; to make; to build.

terato- (English): Pertaining to birth defects and similar...

Definitions

Step	Language	Word	Meaning
1	Ancient Greek	τέρας	sign, marvel, wonder; divine sign, omen, portent;...
2	Proto-Indo-European	kʷer-	to do; to make; to build

terato- — Etymology, Origin & Word History | Etymology Explorer