Esmargot is one of Bea's friends. She is generally laid-back, slimy, kind, and is always sick. She usually has a runny nose. Like most of the girls, she likes Steve Jackson. She is also a secret vampire slayer.
Esmargot's counterpart was Esmarpunzel and was rescued by Oscar ("The Tale of Sir Oscar Fish"). She was put in a bowl by Milo because she sneezed, which Milo said spread germs. She said that year in high school was supposed to be her year to shine ("Milo Gets a Ninja"). In poetry class, Esmargot's poem was "Bunnies are good, bunnies are great, I wish I was a bunny". After Dr. Frog complimented her poem, she said all she can do in this world is try ("The Dark Side Of The Fish").
She was sitting with Milo, Oscar, and Bea at the Hokey Poke once. Esmargot danced when Brandon Bubbler's music video came on. When Bassy took their order, Esmargot ordered a chocolate milkshake because chocolate gives her "pep." They were shocked to find that Albert was there all along. She put a little slime on him to make him visible. Albert thanked her and they both went to get tickets to the Brandon Bubbler concert ("Dollars and Fish"). When Milo was recycling in Freshwater High, he took off Esmargot's plastic hair ties, revealing what her real hair looks like ("Legend of the Earth Troll").
Esmargot was shown to be really bored of Oscar's daily morning announcements. When Bea came and fixed it up, Esmargot stated that she used to feel really bored of the announcements, but she now felt sort of neutral ("Good Morning, Freshwater").
In the "Potatoes for Winter" play, Esmargot played as one of the citizens of El Gratin. She then played as the wind in the funeral scene, having her body hang from a cloud and her slime be the wind. She apologized to the citizens, saying that the slime would wash off with soap ("Fish School Musical"). Esmargot joined the plan to trick-or-treating outside the tanks. Her costume was a ghost. When the gang failed to go through Halloween without Jocktopus stealing their candy, Esmargot said that that's what they get for trying ("Halloween Haul"). Esmargot was seen ribbon-dancing when practicing for the talent show. Esmargot was on Shellsea's side when Shellsea and Clamantha had a big fight after their dancing incident. Esmargot said that she kicks people all the time and it hurts her foot ("Fish Talent Show").
She is currently dating Albert Glass, one of the smartest boys at Freshwater High ("Chicks Dig Vampires", "Glass Man Standing", "The Big Woo"). She said that she likes Albert for his personality, not his voice, when he gains his new deep voice in "Glass Man Standing". They also kissed each other during their graduation on the series finale.
- Her name is a play off of the word "Escargot" and the name "Margaret".
- She and her "family" watch marathons of the long-running Fish British television series "Doctor Hootnane."
- She leaves green slime whenever she walks.
- She feels sick all the time ("Fail Fish").
- She seems to be the only girl to not have eyelashes drawn on her design, and was seen with them only once when Milo removed her hair clips in "Legend of the Earth Troll".
- Although she is a sea slug her backpack has a shell like design making her resemble a sea snail as well.
- She’s a vampire hunter (“Dig Vampires").