- “YOU'RE CA-RA-ZAY, I like it!”
- ―Shellsea, to Bea
Shellsea is a jewel fish and a cheerleader at Freshwater High. She is best friends with Bea. She loves fashion, taking "disco naps", and enjoys shopping, dancing and seeing who is less attractive than her in the yearbook.
Shellsea is very independent, focused and always speaks her mind. She also seems to dislike Oscar. She is a fashion diva and when Bea is not hanging out with Milo and Oscar, she always makes time for Shellsea. Like Bea, Shellsea has interest in the drama club. Shellsea enjoys dancing and listening to hot tunes. She also enjoys putting on makeup or lipstick from her white bag. Shellsea uses words such as Girl and word repeatedly throughout her life.
She had her most major role when Bea was about to do a girls party. Shellsea was bringing cupcakes. When Milo wanted to go to the party, Shellsea told him that sometimes girls like to get together and have fun. When Milo still begged, Shellsea said she's watching him, with her fish eyes. Shellsea and the girls went to Bea's party and when Clamantha suggested to paint her nails, Shellsea pointed out that none of them has nails. When Milo and Oscar came disguised as girls, Shellsea thought they looked ugly. Bea and Shellsea noticed it was Milo and Oscar the first time they saw them in their costumes. Shellsea thought they were spying on them and instead of Bea telling Milo and Oscar to leave, Shellsea tells her that since they are trying to ruin their party, they should ruin theirs. At first Bea disagrees, but later does it. Bea and Shellsea then tortured them and sang Eat Dip. When Oscar admits they're boys, Bea says they already knew. Milo and Oscar told Bea that they thought they were gonna lose her and Shellsea said that who knew boys could be so sweet when they told them they got through all of that for Bea. Shellsea and Bea kicks them out though ("Fish Sleepover Party").
When Milo made his entrance in the classroom, Shellsea enjoys it and says "bring on the party" ("Fish Out of Water"). Shellsea was in the football stadium with Bea, cheering Milo. Shellsea asks Bea if she should cut off her bangs or just leave them. Bea says she's so jealous of Shellsea's hair ("Underwater Boy"). Bea talks to Shellsea on her laptop and talks about boys. Then, Milo, Oscar, Finberley and Koi joins in. But the talk is interrupted by Bea's mom. Bea tells Shellsea to give her giant shoulder pads and makeover when she wants to become an adult. The students are waiting for the school bus, then Bea comes with too much makeover, so Shellsea gets a towel and wipes Bea's face ("Bea Becomes an Adult Fish"). She helps Bea make the queen of the dance by calling her and when the Student Councils asks Bea what happened, Shellsea looked at her in disgust and let her look herself in her mirror ("Queen Bea").
When Milo tried to pass his test, Bea calls her friends to help and when Esmargot sneezes, Shellsea said "ew!" in disgust ("Fail Fish"). Shellsea liked Oscar's sense of humor and laughed at Jocktopus like everyone else ("Funny Fish"). When Bea took a picture of Oscar and Milo's room filled with goo, Bea post the picture to Shellsea, and she said "ew!" ("Dances with Wolf Fish"). Shellsea was one of the many fish who got inside bowls, and she said the white bowl makes her skin look dreadful ("Milo Gets a Ninja"). When Bea tries to get Albert to like her, Bea went to Koi and Shellsea and tells them about it. Shellsea helps by calming her down when Bea went crazy and told her what everyone looks forward to this year, which is the Swirlies, so Shellsea gives Bea tickets. She also gives her a bag that includes stuff like a friendship bracelet ("Fishing For Compliments: The Albert Glass Story"). Shellsea laughed at Milo being weaker than everyone else along with the rest of the girls. Shellsea was impressed with Milo's enormous size and strength, and later ran away when Milo waited too long in the big tank and went to Freshwater, being mistaken for a navy boy monster ("Big Fish"). When Bea was tossing Milo, who is mistaken for a volleyball, Shellsea hit the "volleyball", responding by saying "ew!" ("The Dark Side of the Fish")
Shellsea helped the girls with building their float for the girls vs. boys competition. The result ended up both teams being winners ("Fish Floaters"). Milo once poked Shellsea to see if she was infected by "Fish Brain Parasites", and she had no reaction at all, which made Milo believe she was infected ("Parasite Fright"). Shellsea, along with the other students, fell for Milo's plan to lure everyone out of the tanks for a "Cinco De Milo" party, only to find out they have been fooled by Milo ("Pamela Hamster Returns"). When Milo accused Randy Pincherson for stealing his fridge hat idea, Shellsea told Bea that Randy has been selling the hats for weeks, and was one of the many students who liked Randy's hats rather than Milo's fridge hats ("Milo's Big Idea"). Shellsea got the wrong idea that Bea intentionally wanted to go on a date with Randy Pincherson, who blackmailed Bea to go on a date with him. She was also the first one to throw tomatoes at Randy in the auditorium ("Diary of a Lost Fish"). Shellsea was shown to be really bored by Oscar's morning announcements. She later enjoyed Oscar's announcements after Bea helped him out. When Oscar quit his job as the morning announcer, the cafeteria became closed, making Shellsea and the other students starve ("Good Morning, Freshwater"). Shellsea and the girls joined Clamantha's cheer squad after the old squad got taken out of the tank. Shellsea was shown to be one of the first people to give up after many attempts to complete a routine. She also pointed out in the contest that the hamsters were doing very good, which made the squad more nervous. At the competition, Shellsea and the rest of the team won the trophy for having lots of spirit in their cheer routine ("We've Got Fish Spirit"). Shellsea helped Bea go on a ride with Steve Jackson. They first checked the mirror room, but Bea got too distracted, and Steve Jackson left the area. Shellsea told Bea not to give up when Bea couldn't find Steve Jackson. When Bea got carried away, she started singing emotionally, but before she could even finish, Shellsea snapped Bea out of her dramatic scene ("Good Times at Pupu Goodtimes").
When Milo and Bea told Oscar not to worry so much about winning the perfect attendance award the next day, Shellsea started laughing, saying she finds those kinds of jokes funny ("Run, Oscar, Run"). For the potatoes for winter play, Shellsea played as a citizen of the town, and later played as one of the three cats that was guarding Beastapus's (Jocktopus) castle ("Fish School Musical"). When Bea tried to win the talent show, she got Shellsea and Clamantha to join her dance routine. In their practice routine, Shellsea ended up kicking Clamantha, which caused the two of them to have a huge fight. The whole school later started joining either Team Clamantha or Team Shellsea. In the bathroom, Bea told Shellsea that Clamantha apologized, although she didn't, and Bea only told Shellsea that so she and Clamantha could be friends again and they could continue their routine. The second routine resulted Shellsea kicking Clamantha once again, turning their rivalry become more serious. After Bea got Milo and Oscar to join her dancing routine, Shellsea and Clamantha became friends again after Bea told them that she put them too close together. They ended up winning the talent show at the end ("Fish Talent Show"). It is said by Oscar that Shellsea and the rest if the girls watch Steve Jackson unpack every morning. Shellsea and the girl's crush on Steve Jackson is shown to be extremely huge, as shown in this episode ("Hairanoid").
Shellsea joined Oscar's plan to trick-or-treat outside the tank. When Jocktopus took off with everyone's candy, it is revealed that Shellsea talks about Oscar behind his back ("Halloween Haul"). When Bea had to babysit Ms. Lips's catfish, she told Shellsea, who is in the Burger Bunny with everyone else, to call her if anything surprising happens in there. Shellsea called Bea when Bo Gregory had his car parked and his music playing really loud, and how two girls are wearing the same outfit ("Adventures in Fish-Sitting"). Shellsea didn't make it to the marching band, like all the other students at Freshwater. In the tryouts, she was playing the maracas, but got rejected by Lonnie. At the end, Shellsea and all the students who got rejected joined the battle between Milo and Lonnie ("Banned Band"). Shellsea was skiing with Esmargot and Finberley, and received Milo's invitation to his Christmas party. When Milo and Bea had to deliver presents for Fish Santa Claus, Shellsea told Fish Santa (who was actually Bea in disguise) that he lost weight ("Merry Fishmas, Milo"). Then Milo and Bea saved Christmas.
Shellsea reluctantly helped Piranhica get over her breakup with Jocktopus. Later when Piranhica goes overboard and makes Bea and her friends wear matching uniforms that look like hers, Shellsea was shown to be unhappy with the outfits ("Break Up, Shake Down"). When Bea, Oscar and Milo tried to figure out who glued Mr. Baldwin to his chair, Bea went to Shellsea and asked if she knows what happened during the incident. Shellsea wasn't interested in the question, so she suggested to go see someone smart like Albert Glass ("Milo on the Lam"). Shellsea thought it was wrong when Bea told her that Coach Salmons didn't allow her on the football team just because she's a girl. In the big football game, Shellsea was using her phone rather than paying any attention to the football game ("Just One of the Fish"). Shellsea went with the other students to the camp site, and went off to rescue Milo when everyone thought he was taken by the Yeti Monster ("Rock Lobster Yeti"). Shellsea said that wizards were the new vampires when she and her friends were watching "Wizards in Da House 3". When Bea figured out Milo liked her, Shellsea took her to the girls bathroom and told her that she shouldn't tell Milo she's not interested in dating him due to him recently breaking up with Pamela Hamster, saying that it'll crush his heart. Shellsea then suggested Bea that she should act like she likes Milo so his feelings wouldn't be hurt ("Bea Dates Milo").
When Milo tried to make up a secret admirer so Oscar's feelings wouldn't be hurt, he came across Shellsea, and said he'll give her money if she agrees to go on a date with Oscar, which she reluctantly agrees to do ("Oscar's Secret Admirer").
Bea and Shellsea are the best of friends. Shellsea gives her tips or advice and is seen with Bea everywhere, except when Bea is having an adventure with Milo or Oscar. They both have a lot in common and Shellsea is always there for Bea when she needs her. Shellsea also helped Bea when she tried to be "queen of the dance" by calling her to the Student Council's and letting her see herself with her mirror ("Queen Bea"). Shellsea and Bea usually talk about dating, boys and "girl stuff". Shellsea gave Bea the shoulder pads, shoes and makeup to make her look like an adult ("Bea Becomes an Adult Fish"). They are like sisters.
Shellsea knows Milo, but doesn't hang out with him much. But since Milo is Bea's friend, Shellsea may be just "friends" with him, though Shellsea tortured them for sneaking to their party ("Fish Sleepover Party"). Shellsea was part of the Fishgiving play to help Milo study, but didn't succeed ("Fail Fish"). Like the other students, Shellsea enjoyed Milo's entrance in the class with the eel ("Fish Out of Water").
Like Milo, Oscar and Shellsea's relationship is unknown. She suggested torturing him along with Milo for breaking into the party ("Fish Sleepover Party"). But Shellsea liked Oscar's sense of humor ("Funny Fish") and "aww'ed" when he told Bea he'd miss her ("Bea Becomes an Adult Fish"). Also, Oscar mentions that Shellsea talks about him behind his back ("Halloween Haul").
- Her name is pun on "shell" and "Chelsea".
- She is voiced by Kari Wahlgren.
- Shellsea's biggest role was in Fish Sleepover Party.
- She talks in a slow, valley-girlish voice.
- She is never seen without her handbag.
- It is unknown whether she lives with Koi as shown in "Fishing For Compliments: The Albert Glass Story".
- Her yearbook picture has her putting on lipstick.
- She thought Milo and Oscar looked disgusting with their girl costumes ("Fish Sleepover Party").
- She was dating Steve Jackson, one of the most popular fish in her class ("Doris Flores Gorgeous").
- She seems to be a fan of football and has "fish eyes".
- She seems to get angry when someone is poking her as evidenced in "Parasite Fright".
- She gets angry when one of her friends date an enemy like when she gets angry at Bea for "dating" Randy. ("Diary of a Lost Fish")
- She likes lotions. ("Diary of a Lost Fish")
- Sometimes after Shellsea speaks, it shows a close-up picture with a more detailed face and background singers singing "Come on!", as seen in "Fishing for Compliments: The Albert Glass Story",when she gave Bea the bag with handcuffs.
- Shellsea doesn't appear in Happy Birthfish, Jocktopus, Doggonit, Hooray for Hamsterwood, The Tale of Sir Oscar Fish, Dollars and Fish, Peopleing, Oscar Makes an Impression, Employee Discount, Bea's Commercial And Guys' Night Out.
- Shellsea thinks cattlefish smell like farts.