The Wanderer is a superpowerful being, who is irreverently called The Cheese as a dimunitive nickname. His job is to keep the Balance, or Equilibrium, in check to prevent the second rise of Ragnarok. Currently possessed by the otherdimensional being known as the Head Alien.
The Wanderer began life as an unassuming man named David, who was in love with a woman named Linda Mitchell. Unfortunately, in an incident unknown to the general public, he was brutally murdered by a group of aliens known as the Martians. When she tried to revive him, his soul was sent far back in time to the beginning of the universe, and the Resurrection Chamber which held his body was augmented into the indestructible chassis of the Wanderer.
Sometime during the past, the Wanderer and the Doktor teamed up against and defeated the energy colony known as Ragnarok, sending them into a deep slumber. This caused the Wanderer's obsession with Balance.
After the death of the agent known as Puerto Rico, the Wanderer's body was taken over by the spirit of the late Head Alien, who finds his new nigh omnipotence quite pleasing, if he does say so himself.
Unfortunately, the Alien's power trip would not last long. On his first attempted killing spree, he would tap into the vast power reserves contained within the Wanderer's body. However, doing so also opened the dimensional gate between the prison in which Ragnarok resided and the 'true' world, allowing Ragnarok to escape and destroy the Wanderer completely.