Mordon

Mordon is a human who grew up with Stone Goblins. He was a changeling in that he was swapped as a baby with a goblin child.

Titles and nicknames

 * Goblin Man
 * Mordack

Behind the scenes
It is not quite clear yet but it is strongly suggested that Manny was swapped with Mordon. Mordon grew up with the Goblins, while Manny grew up with humans. Otherwise it's possible Manny kidnapped Mordon, and thus knows identity of the individuals who were swapped.

Most of Mordon's backstory, as well as the specific references to changelings is cut from Chapter 2 (and also does not appear in chapter 3 as well), but can still be read in the script. He would have also had a few lines and interactions with Graham, but these were removed.

By chapter 3 it is now clear that he is a young Mordack (wearing almost the same clothing as from KQ5), and that this sets up further links between the characters from the original series in the reimagined universe.