Charlton Hawkfish is a famous sewer architect who designed the pipes below the Krusty Krab Stadium. He only appears in the episode "The Sewers of Bikini Bottom."


He is a lavender fish with a dark blue dorsal fin and a long saw-like nose. He is also shown to be physically fit. He wears a dark purple suit and a light yellow undershirt with a tie.


When Mr. Krabs visits the newly built Krusty Krab Stadium, he is introduced to Charlton Hawkfish, who was responsible for the construction of the stadium's sewage system. However, he soon grows infuriated when he learned that his client, Crupski, has cut corners in his plans by shorting the main line and built the pipe out of cardboard. His major concern was what would happen during half-time when everyone goes to the bathroom at once. His worst fear has been realized when the whole stadium flooded, so Charlton dove into the water to turn on the fail safety switch to pump out all the water with a giant plunger.

While he is ranting about how the world would come to an end by cheapskates like Mr. Krabs and Crupski, a Sewer Snake comes up behind Charlton, but he defeats the snake by popping it with his sharp nose like a balloon, which blows the snake back into the sewer.