Grentho was a Human male who served as a bodyguard for the droid information broker 8t88. In 5 ABY, 8t88 was hired by Jerec to find the location of the Force nexus called the Valley of the Jedi and soon discovered a Holodisc belonging to the late farmer Morgan Katarn. Unable to decipher it himself, the droid arranged a meeting on the planet Nal Hutta's moon of Nar Shaddaa with Morgan's son, the Rebel agent Kyle Katarn, hoping that he would agree to access it. During the meeting at the Rimmer's Rest cantina, Katarn refused and 8t88 ordered several hired thugs to kill him and 88 left.
Grentho and another female bodyguard joined 88 on his way to the where a shuttle was bound to collect them. After passing a circular door, the trio had to stop as a Gamorrean guard was herding a band of clone slaves in front of them. While waiting, Grentho noticed a tiny, scorpion-shaped tracker droid on the droid's leg; at first the droid didn't let him speak, having ordered him to be silent, contstantly interrupting him until he insisted and pointed out that something was attached on him. While resisting at first, he pried it off and attempted to run away but Grentho caught it with his fingers and notified 88. Seeing it, 88 sensed that it broadcast a signal, and ordered him to destroy it immediately, understanding that it was put earlier on him by Katarn, who wouldn't be far behind. That moment the Furious arrived to pick him up, and to save time, 88 ordered the pilot not to land the shuttle but just lower the ramp.
Indeed, Kyle Katarn announced his presence right after, and the two bodyguards were reaching for their weapons, as Katarn and the droid exchanged taunts; before they could react, Katarn shot his Bryar pistol, dismembering the droid, its mechanical arm holding the disk falling over the edge of the platform. A Stormtrooper helped the droid in as the ramp lifted. The bodyguards and Katarn exchanged a few shots; Katarn's penetrated Grentho's chest, who fell over with his arms open, as if expecting ahug.
Grentho was a very muscular man and was considered one of the brightest 8t88's thugs. He had an addiction to nic-i-tain, as a result of which, his forefinger became stained. His thumb was also heavily callused.
In the audio adaptation of Dark Forces: Rebel Agent, Grentho was voiced by Tim Glovatsky.
The text above follows the novelization where Grentho accompanies 8t88 with a female bodyguard; when Katarn appears, he shoots the droid's arm off before the two bodyguards are able to react. In the audio adaptation, only Grentho appears without mention of the other bodyguard; 88 orders Grentho to delay Katarn while the droid approaches the landing platform expecting the shuttle. Some blaster shots are heard being exchanged before the arrival of the shuttle, and then Katarn shoots off the droid's arm.
- The Complete Star Wars Encyclopedia