"he was waylaid by the Orcs of the Mountains"
is an evil, ugly, goblin-like creature that will kill and eat men. They are used in the armies of Sauron and like to live in dark or evil places, such as the cave-dwelling Orcs in the Misty Mountains, or those that live in Mordor. The Orcs are described elsewhere as being foul creations of Morgoth (or Melkor), one of the Valar (spirits/angels) who turned to darkness and became known as The Great Enemy. Sauron is Morgoth’s servant. See bookmark for page 73 for more about the Valar.
Tolkien revealed that The Princess and the Goblin (1872) by George MacDonald was his main influence in creating the Orcs. On the use of the word ‘orc’ Tolkien said; “Orc I derived from Anglo-Saxon, a word meaning demon”. Goblins can be found in real Germanic and British folklore as mischievous, sometimes evil little creatures that inhabit caves and woodlands. They might possess minor magical abilities and in some stories they eat human flesh.