Ugluk

Was an Orc-chieftain from Isengard. He and a few dozen other Uruk-hai were sent by Saruman on a mission to find the One Ring, which was allegedly carried by one of the Halflings. The Uruk-hai overtook the Fellowship at Parth Galen and took Merry and Pippin as their captives. Ugluk claimed to have been the one who shot Boromir*. The Uruk-host was well under way to Isengard when they were spotted by the Riders of Rohan, and on the brink of Fangorn Ugluk fought sword in sword with Eomer, and was slain by him.

This, however, comes into conflict with the movie version, where Lurtz was the chieftain, and Ugluk took control only after Lurtz was slain.

*In the movie version, Lurtz comes forward instead of him