The port junker is a type of terran UAV. They are used widely at Deadman's Port.
The port junker has no abilities, though it will drop scrap worth 25 minerals if destroyed. Its model is the same as that of the canceled TF-620 Nomad, though smaller.
Blizzard Entertainment. StarCraft II: Wings of Liberty. (Activision Blizzard). PC. Mission: Wings of Liberty, Cutthroat (in English). 2010-07-27.