Grebnedlog was a Pakled starship captain, in command of the freighter Mondor. By profession he was a scavenger, who looked for samples of technology that would make his ship more advanced (or as he put it, "things to make us be strong").
In 2365, Grebnedlog abducted USS Enterprise-D chief engineer Geordi La Forge under the pretense of a distress call in an attempt to make La Forge modify the Mondor and make it "stronger." However, Geordi engaged in a plan with Commander Riker to "deactivate" the modifications made to the Mondor (which Geordi in fact never carried out in the first place) and force Grebnedlog into surrender. (TNG episode: "Samaritan Snare")
Grebnedlog later realized that he had been deceived, and swore vengeance against the Starfleet officers, Riker in particular. The Borg invasion of sector 001 in 2373 gave him such an opportunity, and Grebnedlog boarded the Borg cube and demanded to be assimilated. The Borg would not acquiesce to Grebnedlog's request however, deciding that the mental capacity of the Pakleds as a species made them unworthy of assimilation. As the Battle of Sector 001 progressed, however, the cube sustained severe casualties and decided to embark on an emergency assimilation program, meaning that Grebnedlog was now eligible for assimilation. The Borg placed Grebnedlog in an assimilation chamber and fulfilled his dreams by transforming him into a Borg drone. Unfortunately for Grebnedlog, he died ten seconds later when the Enterprise-E arrived on the scene and assisted in destroying the cube. (TNG - Strange New Worlds 10 short story: "A Dish Served Cold")