In which year, did this earliest guest star in 1999 for SpongeBob SquarePants stop providing the voice?
Mermaid Man and Barnacle Boy Mermaid Man and Barnacle Boy are fictional superheroes in the Nickelodeon animated television series "SpongeBob SquarePants". Mermaid Man was voiced by Ernest Borgnine from 1999 to his death in 2012, and Barnacle Boy is voiced by Tim Conway. Mermaid Man and Barnacle Boy were created and designed by Stephen Hillenburg. The characters debuted on August 21, 1999 in the series' episode "Mermaid Man and Barnacle Boy".
Dunces and Dragons "Dunces and Dragons", also known as "Lost in Time", is the sixth episode of the fourth season and the 66th overall episode of the American animated television series "SpongeBob SquarePants". It was written by Zeus Cervas, Erik Wiese and Tim Hill, and the animation was directed by supervising director, Alan Smart and Tom Yasumi. Cervas and Wiese also functioned as storyboard directors. The episode originally aired on Nickelodeon in the United States on February 20, 2006 as a half-hour special.