It is a large, dark green and light green colored snake with red eyes and big fang-like teeth. It has been shown to eat what would be indigestible objects to humans.
It appears to be hostile towards individuals who enter the sewers it dwells in, as demonstrated on SpongeBob and Squidward in the sewers.
The snake is first seen in the sewers where it pops out of the water and lifts the safe, containing the Krabby Patty Secret formula, with it's nose. The snake then acts aggressive towards SpongeBob and Squidward and chases them through the sewers where it eventually ears SpongeBob and Squidward. However, by tickling the inside of it's stomach, SpongeBob and Squidward successfully make the Sewer Snake vomit both of them out of it's mouth. He later appears in the Krusty Krab Stadium where Charlton Hawkfish uses his sharp nose to pop him like a balloon which sends him flying back to the sewers.