Source: Bestiary 4, pg(s). 132
Aside from trying to batter opponents in combat, this type of golem carries in its trash-encased fists filth and disease. Wounds created by a junk golem often fester and, if not treated, become infected.
The golem also has the unique ability to fall apart into a trash heap, which can independently move about and attack as a debris swarm. This ability is advantageous to the golem as it can then incorporate other junk into its form thereby gaining a small form of regeneration.
The golem's body is crafted from piles of assorted litter and scrap of up to 250 pounds, mixed with another 200 gold pieces' worth of spare metal and copper wire. A skilled arcane spellcaster can then use the wire to enwrap the spare parts into a humanoid form and animate it.