Thrantax the Mighty is a ghost that players must bring under their control during the Merlin's Crystal quest. If they fail, Thrantax will attack them.
He can be summoned an unlimited number of times as long as the player does NOT complete the conversation (this is done by continuing to DROP bat bones once killed). If the player attacks Thrantax as soon as he is summoned one can continuously kill and resummon him again and again for experience.
- While one player summons him to do the quest and is talking to him, another player can fight him and actually kill him.
- He does not count toward ghost Slayer assignments.
- In RuneScape Classic, Thrantax appears as a demon rather than a ghost.
- Although he is a ghost, the Amulet of Ghostspeak is not needed to talk to him.