The Ogre was a fictional version of BIalar Crais that appeared in a mental video game created out of John Crichton's memories. He was terrible axe-wielding monster who was married to the Princess Aeryn -- a fictional version of Aeryn Sun. He had incredible physical strength, and enjoyed killing for fun. All of the other entities existing within the game were terrified of Crais.
Believing that Aeryn was the princess he was intended to kiss, John Crichton and Chiana engaged the ogre and two of his minions in battle. They were able to defeat the minions and, together, kill the Ogre.
Crais the Ogre is derived from Farscape.