Sluggo Star

Sluggo Star is Gary the Snail's father and Herb Star's brother, who is seen on the Starfish Minister's poster in the episode "Rule of Dumb."

Description
He is a small light purple slug with a light green underside. He has yellow eyes, and black pupils as well.

History
At the end of the episode, the elder starfish finds a coffee stain revealing Gary to be Sluggo's son, and the true and rightful king of Bikini Bottom.

Trivia

 * Given that the right to become King was passed to Gary, rather than, this means that Sluggo is the older brother of Herb.
 * Concept art from a scrapped storyline of The SpongeBob Movie: Sponge on the Run showcase that Gary originated from another planet with very different parents. It's unknown if Gary's father on the concept art is Sluggo or another character.