Sayyiduna Abdullah Rahman bin Uthman (may Allah be pleased with him) narrates that a physician mentioned a medicine to the Prophet Muhammad (peace and blessings be upon him) and said that a frog is also included in it. The Prophet Muhammad (peace and blessings be upon him) forbade killing the frog.
Hadith Referenceالفتح الربانی / كتاب الطب والرقي والعين والعدوى والتشاؤم والفال) / 7632
Benefits: … From this it is established that killing the frog is prohibited, so using it in medicine and eating it are also prohibited. From the ahadith of this chapter, it is understood that there is no cure in something that is unlawful (haram) and impure (najis).