Where does “ペーガスス” come from?

ペーガスス (Japanese) comes from Latin Pēgasus, from Ancient Greek Πήγασος.

Ancestry of “ペーガスス”, step by step

Step	Language	Word	Meaning
1	Latin	Pēgasus	—
2	Ancient Greek	Πήγασος	—

ペーガスス — Etymology, Origin & Word History | Etymology Explorer