Mrs. Wormsley is a pink, glistening, meadow worm that has so far, only appeared in the episode Pet or Pests.
At first she seems tame and docile, but from the way she acted, Mrs. Wormsley gets quite angry with Gary. Which makes them fight each other. This is because she and Gary hate each other as they fight like cats and dogs as they are the underwater equivalents. Gary once again fights Mrs. Wormsley and wins the duel, abandoning her newborn litter. Originally, SpongeBob called the worm Mr. Wormsley thinking she was a male. Soon, though, he discovered it was a girl when she gave birth. Gary chased her away from SpongeBob's House and then she took the bus. Mrs. Wormsley had five small babies, and they were sold at the end of the episode.
In the German version she is called "Frau Würmlinger", which means "Miss Würmlinger".