Casey

The Spider-Man was a newborn vampire whose name remained unknown throughout the novella: The Short Second Life of Bree Tanner. He took on the title of "Spider-Man", a Marvel superhero character and was called so throughout the rest of the book.

He was specifically created as an addition to Victoria's army to destroy the Cullen family.

''The Short Second Life of Bree Tanner
This vampire first appeared when he went hunting in the bad neighborhoods of Seattle with Kevin, Bree and Diego, and argued with Kevin about whose superhero figure was better and climbed the walls, imitating Spider-Man's moves before Kevin found a prey and fought for it with "Spider-Man".

Right before their fight with the Cullens, he got into a fight with another vampire named Sara and got his head ripped off.

Physical appearance
The "Spider-Man" kid was known to have blond hair.

Personality
He was depicted as a cocky vampire who enjoyed burning his own kind and fighting in the group. This is partly due to his nature as a newborn vampire.