Mrs. Greenback is made entirely of money, making her light green. Her design resembles feminine attributes. Being inanimate though, there are few features.
Role in series
"Safe Deposit Krabs"
Mrs. Greenback is created by Mr. Krabs after he gets locked in the safe deposit box of the Bank of Bikini Bottom Bank. She is apparently his date and even enjoys a day on the beach with him. However, after the beach catches on fire, Mrs. Greenback is "eaten" by a money dragon, which is actually a vacuum.
The whole thing later turns out to just be in Mr. Krabs' head, because he is running out of oxygen in the bank vault, resulting in hallucinations.
"Fish Food Rescue: The Krusty Krab"
Mrs. Greenback makes a cameo during a brief scene of Mr. Krabs and her dancing inside the safe.