うしがえるじゃなかったです
牛蛙じゃなかったです
ushigaerujanakattadesu

Noun
Desu Copula

The polite, past negative form of うしがえる

1. Was not a bullfrog.; Wasn't a bullfrog.

Past/Perfective
Negative
Polite
Casual Register
Usually Written in Kana