Sandy comes from the state of Texas, but she exhibits many characteristics of a stereotypical "cowgirl" character by going to every city in Texas. She speaks with a heavy southern accent, and uses typical southern slang words and phrases, such as "howdy" and "y'all". She is very fond of her homeland and its culture, as most notably seen in the episode "Texas", in which she grows homesick for it and considers leaving Bikini Bottom to return to Texas. In that same episode, she takes great offense at SpongeBob and Patrick's negative remarks about Texas, and violently attacks them when they continue to insult it.
Sandy is also very athletic and physically fit. She and SpongeBob share a favorite pastime of karate, and frequently fight each other for fun. The karate they use appears to be stylized to fit that of "play karate", as they both mainly fight with chops and kicks in a cartoonish manner. There also appears to be other forms of fighting in the series, most notably in "Karate Island", where three other fish demonstrate unique fighting styles, (which looks more like stylized versions of Kung Fu rather than Karate.)
Sandy also enjoys extreme sports and thrill-seeking, which SpongeBob also joins her in on the occasion, most notably in "Pre-Hibernation Week". Sandy possesses immense strength, and is likely the strongest creature in Bikini Bottom. She is often seen at Mussel Beach lifting weights with Larry the Lobster, of whom she is a good friend, and other muscular fish. In "MuscleBob BuffPants", Sandy shows SpongeBob her immense biceps and an intense daily exercise routine. In that same episode, she wins the eighth annual Goo Lagoon anchor toss competition, tossing an enormous anchor 510 yards.
Sandy is most commonly seen wearing her suit for oxygen when she is outside her Treedome. The suit is white, and with a yellow patch with an acorn on it. It also has two red, and a blue ring(s) on each sleeve. The suit comes with a big glass dome (but it doesn't have an oxygen tank) with a pink flower. She also wears boots with two red dots on the side of each boot. When Sandy appears inside the tree dome, she wears purple clothing, primarily a purple bikini top and a purple and green skirt like bottom. In "Someone's in the Kitchen with Sandy", when her fur pelt is off, she wears a purple bra and purple panties.
When she is on her exercise hamster wheel, she can be seen wearing a white hoodie and blue workout sweats.
Sandy is usually nice, and caring for SpongeBob, and is known to help him out when he's feeling lost as seen in newer episodes, however in older episodes she is shown to be more of a so-called "kook". For example in "Pre-Hibernation Week" she is shown to be more crazy than ever when she forces SpongeBob to play rather dangerous games, thus leaving SpongeBob to run away. She then forced all Bikini Bottomites to search nonstop for days on end looking for him, to the point when they all ran and hid from her just like SpongeBob.
Another example is in "Texas", she cried several times throughout the episode because she missed Texas. SpongeBob and Patrick then made fun of Texas she was offended by SpongeBob and Patrick mocking Texas, and thus she chased both of them down.
She has also been shown to have a strong competitive streak and a high opinion of herself: in "Sandy, SpongeBob, and the Worm", she completely ignores SpongeBob's warnings about the Alaskan Bull Worm and tells him that she is "too Texas tough", only to discover the hard way that the Bull Worm is indeed too much for her to handle; in "Pressure", she continuously brags that land creatures are better than sea creatures and nearly drowns herself in an attempt to "prove" it.
In "Survival of the Idiots," Sandy is shown during her hibernation as an obese, monstrous version of herself (prior to going into hibernation, animals must have tremendous amounts of body fat and energy reserves in order to survive the winter). SpongeBob and Patrick enter her snow-filled Treedome and disturb her sleep, and the semi-conscious Sandy viciously attacks them, believing them to be "Dirty Dan" and "Pinhead Larry", two outlaws from her dreams.
In "Texas" she chased and tried to beat up SpongeBob and Patrick for "taking the name of Texas in vain".
In "Survival of the Idiots", Sandy beat up SpongeBob and Patrick whenever they woke her up. That may be because they were interrupting her necessary hibernation and she did not know what she was doing.
When she was an adult she joined a company called Treedome Enterprises. This company sent her down to Bikini Bottom.
In Bikini Bottom, she met SpongeBob SquarePants while she was fighting a clam. She also met Patrick Star the next day when he tried to save SpongeBob who was at Sandy's treedome for tea and SpongeBob got all dried up because there is no water in her treedome. She has also met many other sea creatures since she arrived at Bikini Bottom.
Sandy lives in a huge polyurethane dome which is known as the "Treedome". It is air-locked and contains no water, making it the only place in Bikini Bottom where Sandy can survive without her suit. Its floor is covered in grass, and features a large tree, which contains Sandy's living quarters. The Treedome also humorously includes a giant hamster wheel, among other backyardish things. As seen in the episodes "Survival of the Idiots" and "Bubble Buddy", the dome produces snow during the winter, from which it can be assumed to simulate other weather patterns as well.
As seen in the episode "Wormy", Sandy has many pets residing in her Treedome, including caterpillars, snakes, crickets, mice, and birds, among others.
The company that owns this and many other treedomes is the Tree Dome Enterprises Limited. Its board of directors, a group of chimps, came for an inspection in "Chimps Ahoy." Her old habitat was back home in Texas.
SpongeBob: Sandy first metSpongeBob SquarePants when he saw her wrestling a giant clam and ran down to save her. Since then, Sandy has been one of SpongeBob's best friends, and she enjoys various activities such as karate with him. The nature of Sandy's relationship with SpongeBob is somewhat romantic. SpongeBob has brought her flowers on several occasions, and her official biography describes her as being "the apple of SpongeBob's eye (the only thing under the sea he likes better than his job at the Krusty Krab)". In "Tea at the Treedome" amorous music plays when SpongeBob recalls Sandy's words. SpongeBob's song in "Ripped Pants" has romantic lyrics. Many fans believe that SpongeBob and Sandy have crushes on each other. In "Frozen Face-Off", Sandy sacrifices herself to let the monster eat her instead of SpongeBob, who sacrifices himself to save Patrick, but it ate the jellybeans instead.
In the "A Random Act of SpongeBob" short, SpongeBob leaves Sandy a letter (with a bouquet of flowers) calling her the "smartest, prettiest squirrel in all of Bikini Bottom" for "Surprise Sandy Day". In the video game Battle for Bikini Bottom, after saving Squidward from Robo-Patrick, SpongeBob and Sandy commented each other on a good job while looking flushed. A book called the SpongeBob SquarePants Survival Guide, released on November 1, 2002, has a page titled How to Survive a Secret Crush, saying that if you have a crush on someone, you have to keep it secret. SpongeBob begins to talk about him acting "perfectly natural" at the Treedome, but quickly ends, saying "I've said too much!" The biggest hint was in Truth or Square, which depicted the two getting married.
Mr. Krabs: Sandy and Mr. Krabs don't really talk to each other, however there are a few episodes when they do talk. When they do, they seem to be very nice to each other and they never really fight.
Patrick: Patrick and Sandy have an unusual friendship but, when they are seen with SpongeBob they tend to get along very well. However Sandy has numerously been annoyed by Patrick's utter stupidity.
Squidward: Sandy and Squidward usually get along, however there are times where Sandy is angered by him such as in "Truth or Square" in which Squidward is mistakenly blamed for stealing a walkie-talkie that Patrick "borrowed". Then in "Squid Defense", She and SpongeBob were upset at Squidward when he used karate to beat up a seemingly creepy guy which turned about to be only after Squidward to return the groceries he dropped in their earlier encounter.
Plankton: Sandy tends to dislike Plankton, such as in "Someone's In The Kitchen With Sandy" when he stole her fur to steal the secret Krabby Patty formula. However they did get along in "Perfect Chemistry" as she was impressed by his lab and she knew that Plankton was planning to steal the Krabby Patty formula.
Pearl: Sandy and Pearl do not really talk to each other, but in Texas, Pearl wanted Sandy to stay in Bikini Bottom. In Bubble Troubles, Pearl helps Sandy breathe air, saying "I guess us mammals have to stick together".
Sandy appears in almost all SpongeBob Video Games usually as a playable character and sometimes (rarely) as a major non-playable character.
SpongeBob SquarePants: Revenge of the Flying Dutchman- In Revenge of the Flying Dutchman she is a non-playable character who is seen in various parts of Bikini Bottom, first, SpongeBob does Karate with her, then, she needs help clogging up some holes in her treedome and then she needs help getting a beehive out of her tree (SpongeBob thought it was a big acorn), in Downtown Bikini Bottom she needs help disposing some garbage and is later hypnotized by the Flying Dutchman and needs to be rescued along with Squidward, Patrick, Gary and Mr. Krabs.
SpongeBob SquarePants: Battle for Bikini Bottom- Sandy appears as one of the three playable characters, the other two being SpongeBob and Patrick, she is unlocked in Downtown Bikini Bottom, she also fights Robo-Patrick when SpongeBob and Squidward are frozen, she also defeats the Flying Dutchman alone, when he refuses to give them a golden spatula, she is an extremely useful character, as she can do karate and use her lasso to glide after doing a double jump, swing from Texas Trailer Hitches and Tie up robots before they even get close.
SpongeBob SquarePants: Employee of the Month- She helps SpongeBob and Patrick get to Neptune’s Paradise with her Rocket, but when it breaks down, they land in Bottoms Up and it is revealed that she has a friend named Cowfish Craig and knows about Oxygen Springs.
SpongeBob's Atlantis SquarePantis- Sandy appears as one of the seven playable characters, the other six being SpongeBob, Patrick, Squidward, Mr. Krabs, Plankton, and an Atlantian Guard, her special ability is her lasso.
Nicktoons Unite!: She helps guide the heroes through some of the first SpongeBob level. At the end of the level she explains what has happened in Bikini Bottom. She also tells the heroes that they have an agent in Jellyfish Fields (Patrick).
Nicktoons: Battle for Volcano Island- Sandy appears as one of the playable Nicktoons, the others being SpongeBob, Danny Phantom, Patrick, Timmy Turner (along with Wanda and Cosmo) and Sam Manson, this is the only video game where Sandy's Karate Gear appears as an attack.
In Season 1 episodes, Sandy's tail is not visible when she is wearing her suit in comparison to later seasons.
Despite being established as a scientist in later episodes, Sandy is oblivious to the basic fact that sea creatures cannot survive without water in her first appearance. Although, it may be because SpongeBob told her that he likes air not knowing that she meant without water. It is also possible that she thought he was a kitchen sponge, due to his appearance and the fact that kitchen sponges do not need water.
She appeared the most in Season 8, having a total of 17 episode appearances and one short appearance.
In the live-action puppet sequence in the episode "Pressure", Sandy is represented by a toy puppet and appears to be naked aside from her helmet.
"I sure wish I had a fancy telescope. One that works underwater. That'd make me happier than a junebug at a porchlight sale!" ("Wishing You Well")
I'll be over there faster than a barefoot jackrabbit on a hot greasy griddle in the middle of August!" ("Suds")
"Why don't you say that to my behind; that is, if you can catch it!" ("Pressure")
(IN SONG) "Wish I were back in Texas. The ocean's no place for a squirrel. Wish I was in Texas, perr-tiest place in the world, Oh No! I know that deep in my heart, I'll always be a Texas girl." ("Texas")
"Howdy y'all!" (Multible episodes)
"SpongeBob of all the crazy things, why would you wanna live among the jellyfish? They're cold and mean and none too bright!" ("Nature Pants")