Stanley seems to wear clothing extremely similar to SpongeBob's, except for the lines SpongeBob has on his pants, which means that Stanley and SpongeBob are considered to be like brothers to each other, brotherly cousins if you will. According to Mr. Krabs, he looks like, smells like, and tastes like SpongeBob.
He appears to be the tallest member of the SquarePants family.
Abilities and Talents
Stanley cannot do "anything" right, anything he tries will fail horrifically regardless of how simple and inconsequential it would be for another person (for example, simply touching SpongeBob's TV resulted in it exploding) and can't even do nothing. His sole talent would appear to be destroying things without even trying, which Mr. Krabs used to destroy the Chum Bucket. However, he does have several abilities to point out:
He seemed uninjured when the Chum Bucket exploded with him at the interior.
He was capable of squeezing in a cardboard box which is small compared to his body.
He willfully tries to attempt to find a hobby or occupation, always resulting in chaos or failure. Appearing to be amazed by SpongeBob's lifestyles, he skims his house touching everything from the toilet to the television. Despite knowing that he breaks anything, he comes in contact with using his hands. He has little care for the property.
When Stanley took a job at the Krusty Krab, he shows no regard for SpongeBob, who took the blame whenever Stanley sets something on fire, causing the better worker to be put on probation. He took pictures of his first customer and in one he kissed him when he was wearing a wedding dress, and he got mad and Stanley took another picture of him when Stanley pretends to be mad at him. The customer gets even more angry and explodes (litterally). He makes SpongeBob do all the work of ordering and cooking, and mess his station, while Stanley prints his photos. He breaks SpongeBob's spatula and he couldn't take it anymore, so he confesses to covering for Stanley.
In the episode "Stanley S. SquarePants," he was sent to live with SpongeBob for somehow breaking everything he touches and not being able to do anything right. SpongeBob helps him out, only to fail at first. Mr. Krabs finally helps by giving Stanley a job at the Chum Bucket, much to his amusement when Stanley destroys the restaurant.
It is unknown of what employment he has, but the conclusion, where all of his applications were turned down, is plausible. During this episode, he attempts to become a scientist when visiting Sandy but was recommended against it. He took a job as the cashier in the Krusty Krab and failed. When Mr. Krabs realizes this, he gave Stanley the assignment of destroying the Chum Bucket.
His episode noted that he lived with his father, Sherm. Stanley stated he doesn't have several things in his house, unlike SpongeBob.
Sherm doesn't let him touch anything in his house (even the toilet), since he would destroy it on contact.
According to Mr. Krabs, Stanley smells exactly like SpongeBob.
Stanley is one of a few relatives of SpongeBob who isn't a sea sponge.