This article's content is accurate to the most recent public game version, 0.4.8d.
The Frog In A Pond Game Over is an ending which occurs when losing against the Hungry Treasure Chest.
In order to to get this ending, Eric(a) need to be a man and lose as a man.
After he loses, Marianne shows up and pulls him out of the chest. Afterwards, she questions why he was here, but before he can respond, she asks why the treasure chest, which only eats men, attacked him. She then lifts his dress and examines him. Finding out Eric(a) is male, she immediately turns him into a frog in which he spends the rest of his life as. Although on the plus side, Marianne didn't want frog legs.