Croaker is a typical old frog who has lived for a really long time. She comes off as a friendly, yet frail old woman who is willing to lend an ear or offer kind words to those she meets. She is a very private person and tends to keep quiet about herself. However, underneath all that lies a crafty woman with a hint of feistiness about her. Croaker can be a wily septuagenarian if provoked and has pulled the rug over those that are the target of her scorn (such as Sprig whom she has a love-hate relationship with). If someone is being indirect with her she will go out of her way to teach them a lesson.
Croaker is a light violet colored frog with a violet-pink underbelly and four fingers and, presumably, two toes. She has a tall fluffy grey hair, a darker purple spot on her head (most likely a liver spot) and noticeable wrinkles. She also has distinctly frog like eyes (ironically as the other frogs have typical cartoon eyes) that are pale yellow with her left eye having a black pupil and her right eye having a milky grey pupil.
Dress wise, she wears a brownish rag dress and a white neckerchief slung over her back. She has light black slippers and to top it all off has a walking cane which she is shown to be proficient in using as a weapon.
- Martial artist: Sadie has shown a hidden ability to defend herself in combat whenever situations get tough.
- Covert skills: Sadie is a former super spy and occasionally uses them to continue work even after her supposed retirement.
- In "Cracking Mrs. Croaker", Croaker states that she does not like Sprig, but she is shown interacting with him in episodes like they have a mutual relationship.
- The fact that her name is "Mrs." implies that she was married at one point.
- She does not want anyone knowing about her background as a spy because according to her, "it would be very bad for everyone."
- According to Maddie Flour, she smells like wet leaves and fungus.
- Stumpy seems to not think much of her.
- Leopold Loggle states that she looked the same when he was a kid.
- She has been shopping at Plantars' since she was a little girl and apparently knew Hop Pop's father.