Mr. Krabs' Nephews are a group of triplets that resemble their uncle, Mr. Krabs. According to Mr. Krabs, they solve mysteries. They wanted a job at the Krusty Krab only to be turned down by Mr. Krabs. They were also told to solve the mystery of why they didn't get the job. They only appeared in the episode Stanley S. SquarePants.
They're the cousins of Pearl. Their only known quotes are "But Uncle Krabs" "Grumble, Grumble, Grumble...".
Mr. Krabs says that they love to solve mysteries. This is most likely a reference to Duck Tales.
They must also be a parody of Popeye's nephews from the series Popeye.
This reveals that how Mr. krabs have a sibling(s).