Seth

Sid is a human in the Armada portion of the Unicron Trilogy continuity family.

Not Billy and Fred.

Sid is a mean, aggressive pre-teen who spends his time slingshotting rocks at squirrels. He and his friend Seth love to bully total nerds, so living in Science City must be like Christmas for them. Of the two, Sid is clearly the more dominant, pushing Seth around nearly as much as he does his actual targets.

This is how he is distinguished from the spineless Fred, Sid's doppleganger who attends the same school.

Fiction

Dreamwave comics continuity

Armada

From Teletraan I: The Transformers Wiki, a Wikia wiki.