Uglúk

"Food and rest in Isengard!"

- Uglúk to the hobbits Uglúk was an Orc captain in service to the wizard Saruman.

The Battle at Amon Hen
While searching for Frodo Baggins, Merry and Pippin bump into the horde of Orcs from Moria that had pursued them from the mines to avenge the death of their chieftain and capture thee halflings.

Uglúk attempts to get his hands on them, but is interrupted by Boromir who rescues them, before being shot by several archers. The hobbits are then taken prisoners by the orcs.

To Isengard
"Grishnákh! Grishnákh!"

- Uglúk yelling at Grishnákh Uglúk takes command over the orcs and is revealed to be in service to Saruman, who has tasked him with retrieving the Hobbits.

He leads the band towards Isengard but often finds himself quarreling with Sauron's soldiers who wish to take the captives to Mordor. He disagrees and when the captives ask for food he tells them that they shall get good treatment where he shall take them and later steals a draught from Grishnákh after they asked for water. He orders them to be whipped if they do not run fast enough on the road through Rohan.

Uglúk realizes he is being followed not only by Aragorn. Gimli and Legolas but also by the Rohirrim Riders whom he is forced to battle near the eaves of Fangorn Forest. He gives orders to the orcs to guard the two hobbits in order for them not to escape Saruman's grasp. His ultimate fate is unknown.

Trivia

 * In Ralph Bakshi's The Lord of the Rings, Uglúk has apparently taken command of the Orcs after the death of the Orc Chieftain, being from Moria.
 * He is not an Uruk-hai but rather a larger Orc similar to the orc chieftain from Moria.
 * In the novel he is killed by Prince Éomer during the ambush at the eaves of Fangorn Forest at night.