Sam is a large, obese, and muscular sea star with dark pink skin with red dots. She is roughly twice the size of Patrick. She has black hair which she wears in a side ponytail that is fastened with a light lime green scrunchy. Her outfit consists of a blue-violet top with flowers that are the same color of her hair scrunchy, as well as a matching skirt. Sam has a very deep voice; similar to a caveman's (despite usual females having much higher voices). She often calls herself "Sister Sam." She can literally put on her mean face whenever she completely loses her temper by turning her head around. She becomes very aggressive and destructive and can end up destroying anything.
Sam is shown to be highly aggressive by her clarity. This can be true as she is easily angered by any person she does not recognize. However, she expresses a brotherly bond with her younger brother and defends him from the other neighbor SpongeBob when she mistook physical contact as aggression. In addition to her supportive behavior, her level of intelligence is relatively lower than Patrick's as she speaks incomplete language and has no regard for other people. She talks in third person.
She was lost in a surf when she and Patrick were kids. Patrick had possibly forgotten about it, due to the fact that in the episode "Something Smells," he says that he does not have a sister.
It is unknown what happened to Sam, but she was most likely saved and raised by another family.
Sam comes to town to visit Patrick. She then gets very violent and aggressive, brutalizing SpongeBob and Squidward's houses. Squidward angrily objects but she gets angry at him. She steals stuff from Squidward's house until it disintegrates.
Sam was shown only in "Big Sister Sam" and it is unknown if she will ever appear again.
Sam is the only known sibling to Patrick.
Sam mispronounces "brother" as "brubber" and "decorate" as "blecorate."
Sam is one of the strongest characters in the series.
Even though she thought SpongeBob was one of the "meanies," she probably likes him more than Squidward since SpongeBob tried to save their house and help Patrick wake up.
She could be a reference to the Incredible Hulk, due to her speaking in the third person, and her exceeding strength.
She has the same hair color as her mother.
In the episode Something Smells Patrick mentions how he doesn't have a sister, although his sister is Sam.
"Yellow square touch brubber! Makes Sister Sam MAD!"
"If Big Nose no like sand, BIG NOSE MOVE!"
"Those boys mean! They pick on Sister Sam!"
"You mean... blecorate?"
"Sister Sam rearrange NOW!"
"Yellow square make brubber's eyes water!"
"MEANIES GO HOME!"
"Meanies is mean."
"Patrick okay! Sister Sam feel bad. Sorry she hurt Patrick. She protect little brubber." She go now."