Scavenger (The Sontaran Experiment)

Sontaran Field Major Styre created a robot on Earth to help him keep the GalSec astronauts in line. Little was known about its internal workings or capabilities. It used a form of grappling cables to incapacitate and capture humans. However, the metal Terullian was used in the robot's drive system, and it was easily disabled by the Fourth Doctor's sonic screwdriver. (DW: The Sontaran Experiment)