He is know to be very cheap, where even in the episode "Krabby Land" SpongeBob calls him Cheapy the Cheapskate, showing that he can be too cheap at times. It is unknown how his daughter is a whale. Though it may have been Mr. Krabs adopted her or his wife was a whale. His arch enemy is Plankton also known as Sheldon J. Plankton but usaully just called Plankton.
He owns the Krusty Krab which is one of the most popular resteraunts in Bikini Bottom. He only has two people that work at the Krusty Krab which are SpongeBob and Squidward, though sometimes there are other characters that work there such as Patrick, Gary, and Mrs. Puff. He is also known to have dated Mrs. Puff in the past as seen in the season 2 episode "Krusty Love" but now it appears what they use to have is gone, with Mr. Krabs disliking her as revealed in the season 7 episode "Summer Job."