Fizzy Walnuts was a land squirrel, the Swedish cousin of some loser named Fuzzy Acorns, and legendary Blacker Belt Master in karate, who has so much skill that not even the great Dragon Warrior stands a chance of beating him (but then again, the Dragon Warrior has never been good at defeating things).
In some time he and his deceased cousin "Fuzzy Acorn" are friendly and honestly masters of the karate, One day, Fizzy Walnuts was defeated by Fuzzy Acorns then every people includes Fuzzy Acorns and Sandy Cheeks tease him, Fizzy was shocked by the scene and his mind was corrupted and his body deformed.
After that, Fizzy Walnuts screams and kills, mutilates and scrunch Fuzzy Acorns, Sandy Cheeks and SpongeBob were traumatized by the scene, Fizzy escapes from the scene and starts to kill everybody in his road.
Later, Fizzy develops an intellect superior of all the scientists in the world, becoming the morbid acorn most intelligent in the universe and he is planning to use that skill to the evil.
He used to live high up in the mountains, occasionally coming out of his cave to fight Morton Koopa Jr., but after his rival Walleo moved the Weegee Troops underwater, Fizzy came down with him and joined the Skodwarde Squad to get closer to Weegee and finally finish him off. Legend has it that Fizzy is now teaching his Blacker Belt moves to a younger karate prodigy to continue Fizzy's legacy should he fail to kill Weegee before his time expires.
Fizzy is the first and only (so far) Skodwarde Squad member to not be a sea creature of any kind. He's also the only land squirrel living in Bikini Bottom who doesn't need an air helmet to live (he is so awesome, he just pulls the oxygen out of the water!). For some reason, though, Fizzy always has a pained expression on his face.
Fizzy has been proven to be completely defenseless against Tobuscus because Tobuscus is so weird, Fizzy feels too uncomfortable to fight. He now spends most of his free time in his underwater cave watching creepy YouTube Poops to fix this weakness.
Following the death of Skodwarde, Fizzy had to work alone because the squad was dissolved by Moar Krabs. At midnight Fizzy was alone when Gohan Blanco appeared out of nowhere. Fizzy stepped back thinking that it's impossible. Gohan Blanco then blankly said "Esto es el fin, Fizzy Walnuts!" Gohan Blanco then released a powerful masenko to Fizzy, reducing him to dust in the process. The reason for Gohan doing this was because Fizzy stole Shaggy's scooby snacks and ate them.
- Fizzy hates M.Bison and I.M. Meen.
- Fizzy has an IQ superior to that of Dr. Robotnik's.
- Fizzy hates SpongeBob and Tobuscus
- He was responsible for the disease of Spengbab.
- He can give you nightmares if you look into his face for more than 2 minutes.
- The Skodwarde Squad
- Fighting Koopalings (especially Morton)
- Being the proud wearer of a Blacker Belt
- The Krusty Krab
- Sandy Cheeks
- Being in harmony with the Universe
- Or better yet, being in control of it
- Great Mighty Poo
- Using an air helmet
- Unworthy students
- Being defeated in battle
- Frank Woods (Thinks he can do better than this morbid rat)
- Lex Luthor (Always telling him that he's WRONG!!)
- Pills (Doesn't need them)
- Ronnie McDoggle