Eric, of Samneric, the twins on the island is a steady character throughout the novel Lord of the Flies. It is difficult to speak of one of the twins without speaking of the other, because they always did everything together. Piggy even notes:
"You've got to treat Samneric as one turn. They do everything together--" (138).
Originally introduced along with the other boys respond to the call of the conch, Eric and his brother are like book-ends in this quote:
"The two boys, bullet-headed and with hair like tow, flung themselves down and lay grinning and panting at ralph like dogs. They were twins, and the eye was shocked and incredulous at such cheery duplication. They breathed together, they grinned together, they were chunky and vital" (19).
Golding's simile "like dogs" is an apt comparison for Sam and Eric, because they remain incredibly steadfast and loyal to Ralph throughout the entirety of the novel. They stick by Ralph even when all of the other hunters join Jack. Sam and Eric are also the only other boys that Golding has showing remorse after Simon's death.
Sam and Eric are practically interchangeable in Lord of the Flies. When included in the dialogue of the story, the characters frequently finish each other's sentences:
"Listen, Ralph. Never mind what's sense. That's gone--"
"Never mind about the chief--"
"--you've got to go for your own good" (188).
Even in the end when Jack forces them to be on his tribe, both Sam and Eric still try to help Ralph, warning him that Jack is out to get him and "sharpened a stick at both ends" (188).