I think you might be looking for episode 8 of InuYasha, "The Toad Who Would Be Prince".
I took a guess and replaced "frog" with "toad" and then ran some searches.
A DuckDuckGo search for "anime" "toad" girls spheres (and I had to quote it like that, and use DuckDuckGo, and rerunning the query now gives different results omitting the key link) got me to the InuYasha yōkai list which is a list of demons appearing in the anime series InuYasha. In the list was "Tsukumo no Gama (Toad of Tsukumo), also known as the Toad Demon". A DuckDuckGo search for Toad of Tsukumo then led me to this image:
In case that image goes away, here's a second link and an archive.org copy of the second link.
This seems to match your description. The image link told me the episode is called "The Toad Who Would Be Prince" and a DuckDuckGo search for "inuyasha" "the toad who would be prince" got me to a summary of the episode. The key point of the plot that matches your description is:
The toad then takes Tsuyu to a room where it has been holding other princesses in egg sac-like prisons; it turns out that the toad eats young women's souls to stay alive. Inuyasha attacks the toad with Tessaiga, managing the inflict a wound on its' shoulder. However, the toad calls forth the souls from some of the women it has captured and its' wound is healed instantly.
If that's not it, you might want to look at Anime Planet's list of frog characters.