Jesse Grass is the teenage leader of a club called Dirt First, which protests against things that are harmful to the environment, like the Krusty Burger. He is a level five vegan, meaning that he refuses to eat anything that casts a shadow. Lisa fell in love with him.
His latest known protests were against Krusty Burger and against the Springfield's oldest redwood tree being cut down. He was thrown in jail for his protests, but later freed, only to be thrown in jail again after he cut down the log of the redwood tree with a "Lisa-Land" sign at the top, which demolished much of the Business district.
Jesse attended the Green Day concert with the rest of Dirt First.
 Behind the Laughter
According to Matt Selman, the writer of the episode, says the character is named after Selmans' brother, Jesse, who was in a band known as "Grass".