The Prehistoric Krabs are the prehistoric ancestors of the modern Krabs family. They are seen briefly in the episode "Ugh," in which they are squashed and eaten by SpongeGar. A bunch of crabs run from Patar after he lifts a rock and they say only "money" constantly.
King Krabs was a medieval monarch of Bikini Bottomshire sometime before the 12th century. He is an ancestor of the modern day Krabs family, including Eugene H. Krabs and Pearl Krabs. He has one daughter, Princess Pearl, who resembles the modern day Pearl Krabs. He is enemies with Planktonamor, an ancestor of Sheldon J. Plankton. He appears in the episode "Dunces and Dragons."
Princess Pearl Krabs is the princess of Bikini Bottomshire during her father's reign and an ancestor of Pearl. SpongeBob, Patrick, Squidly Tentacles, and the Dark Knight must rescue her from Planktonamor.
Princess Pearlina Krabs is a princess who lived during the Dark Ages. GrandPat helps her dragon recover from a toothache. She appears in the episode "The Yard Sale."
A prospector relative of Mr. Krabs lived during the Old West. GrandPat attempts to sell him a vacuum and cleans out his cave. He appears in the episode "The Yard Sale."
Great-Great Grandpa Krabs is mentioned in "Pest of the West" by Mr. Krabs, who said that he invented a money security system. He appeared physically in "Senior Discount."
Betsy Krabs (or Betsy Quaterkrab) is Mr. Krabs and his unnamed sister's mother, the sister of Alan, as well as the grandmother of Pearl and Mr. Krabs' three nephews.
Great Grandpop Krabs is mentioned in "The Curse of the Hex" when he mentions that there are no such things as curses. He makes his first physical appearance in "Senior Discount." He is also the father of Sally.
Mr. Krabs' Grandma is Mr. Krabs' grandmother, Redbeard's wife, and Krabs Senior's mother. Not much is known about her but she gained a pair of false teeth that were made out of cardboard after marrying Redbeard. She has never appeared physically in the show, but was shown on a picture in Mr. Krabs' wallet in "The Sewers of Bikini Bottom," and on the tattoo on Mr. Krabs' chest in "Grandmum's the Word."
Krabs Senior is Mr. Krabs' father who is first mentioned in "My Pretty Seahorse" when Mr. Krabs tells a story in which his dad gave him a one dollar bill, which he loved, when he was five. He also appears in an old photograph in Betsy Krabs' house. There is also a picture in Mr. Krabs' office in "Gullible Pants" that could be him. He first physically appears in the episode "Senior Discount."
Sally Krabs
Sally Krabs is Mr. Krabs' grandaunt who is never seen, but is mentioned in "SpongeBob SquarePants vs. The Big One" when Mr. Krabs promises the Flying Dutchman that he will not spill his groceries again, and telling him that Sally wore false teeth, but the Dutchman thinks Mr. Krabs is lying because he knew her because he dated her in high school (however, it's likely this was before she got false teeth). She is also the daughter of Great Grandpop Krabs, and is the sister of Redbeard Krabs.
Alan Quaterkrab is Mr. Krabs' uncle and Betsy Krabs' brother, since he has a different last name than his nephew. He seemingly never married and without children, Alan died at some point before the series began, leaving all of his belongings to his nephew.
Eugene H. Krabs (born November 30, 1942) is a red crab who lives in an anchor with his daughter Pearl. He is the owner and founder of the Krusty Krab, where he works as SpongeBob and Squidward's boss. Mr. Krabs is obsessed with money and can be very selfish.
Mrs. Krabs is Eugene H. Krabs' either deceased wife or ex-wife. In SpongeBob SquarePants Trivia Book, Mr. Krabs says that Pearl "takes after her mother," which indicates that Mrs. Krabs is a whale. Mrs. Krabs has somehow left Bikini Bottom, although the details are unclear.
Pearl Krabs is a whale who lives in a hollow anchor with her father Mr. Krabs. When she grows up, her father wants her to continue the family business by inheriting the Krusty Krab and becoming its owner. She's always chatting with her friends and talking about things that are only of interest to teenage girls. She's revealed to be 16 years old in the episode "Whale of a Birthday."
The three nephews of Mr. Krabs who appear in the episode "Stanley S. SquarePants." This also shows that Mr. Krabs has a sister who is never seen. It has to be female because Redbeard Krabs said that Mr. Krabs was his only grandson. (If they have the last name "Krabs," their mother didn't change her last name). The nephews are the cousins of Pearl Krabs and the great-grandsons of Grandma and Grandpa Krabs.
