PD 4786 was an Imperial Viper probe droid, identified by that designation, that Jerec sent to Ruusan in 5 ABY.
In contrast to other viper droids, this particular model was armed with four energy cannons, positioned at each cardinal direction. It carried Holocameras, but during the night, it relied on heat sensors. A targeting laser was sometimes activated during its attacks.
The droid arrived on the planet on a night when the network of sixteen smuggler-operated satellites had been rendered inoperative. Grif Grawley aiming at PD 4786. Colonist Grif Grawley, using his electrobinoculars from Hill_461 while searching for Bouncers, noticed it. The heat signature and altitude indicated it to be a droid, not a Bouncer. He tried to take it out with his blast rifle, but his initial shot missed. His subsequent shot damaged one of the sensors. The droid retaliated, destroying a portion of his windshield, but he was able to move the speeder out of the path of the second shot.
Ultimately, he eliminated the droid by deliberately crashing his airspeeder into it. The droid remained fixed on the incoming speeder until the moment of impact, resulting in an explosion. Grawley recovered the probot's identification plate and took it to the Smuggler's Rest tapcafe in an attempt to warn Fort Nowhere about the potential for an impending Imperial attack.