Martha Smith is a minor character that appears in the series. She is the wife of Tom and is mostly seen in angry mobs (even leading one in the episode The Krabby Kronicle). She is also a professional harpist in an orchestra.
Martha is an aquamarine fish who wears a light purple dress and red shoes. She is pretty tall in height compared to others. She also carries a purse. Martha is sometimes seen with Harold Smith, and Tyler might be their son. She also used to date Nat, and appears to be very rich. Martha is usually mad at Mr. Krabs, and hits him with her purse, or leads angry mobs against him.
In Wigstruck, Martha is seen in a movie saying, "It's true John. This isn't my real hair, I stole it!" and she takes off her wig.