You're not killing the frogs though, they turn into Blupees. Personally I think it's based on Buddhism and freeing them of their attachment to desires, since in Japanese the Bubbulfrogs are called マヨイ (*Mayoi*). *Mayoi* (迷い) literally means "getting lost" but it's used in Buddhism to mean "inability to achieve enlightenment", and the word for enlightenment is 悟り (*satori*). So I think Blupees who follow the wrong path become Bubbulfrogs, and those who attain enlightenment become a Satori.