The frog recognizes the superior talent within the song of the nightingale. In seeing the threat to his own position, the frog adopts the guise of a mentor to the unwitting nightingale. The first stage in bringing on her death and downfall is through tempting her with the lure of fame and adulation, and the promise of being "a winner:"
Proper training such as I
- And few others can supply.
You'll remain a mere beginner.
But with me you'll be a winner"
The frog is able to lure her with the promise of "winning" and this becomes her motivation to take his tuition without question, referring to him as Mozart after he issues her the challenge of his "tuition."
The frog's training program is what ends up ushering the downfall of the nightingale. The initial phase of this program is having the nightingale practice in challenging weather. The frog has her sing in the rain, when her voice is impacted by the elements. This workout continued for "six hours till she was shivering and her voice was hoarse and quivering." The next phase involved depriving her of sleep and causing her voice to be even more debilitated. The weakening of her voice caused her song to become "sorrowful and pale." The adulation she loved so much was dwindling because her voice no longer carried her own charisma and spark that it once possessed. In getting the nightingale to "puff your lungs," she burst a vein and died.
The frog was able to facilitate the downfall of the nightingale in the way he earned her confidence. This "roping of the mark" enabled him to violate her trust, eliminating her as his competition in Bindle Bog.