Ancient Ogre

Ogre is first mentioned in Heihachi Mishima's character profile. It states that many years after Heihachi had reclaimed control of the Mishima Zaibatsu, he forms the Tekken Force, his own military group. One of the missions of the Tekken Force is to search an ancient temple located somewhere in Mexico. Soon after arriving there, Heihachi learns that his entire force has been obliterated by Ogre. Heihachi, having witnessed the power of Ogre, seeks to capture it in hopes of creating the ultimate life form.

According to official canon, Ogre attacks many world-renowned martial arts masters around the world and absorbs their ki and abilities into his own being. Ogre eventually makes his way towards Yakushima, where Jun Kazama lives with her fifteen-year-old son, Jin. Ogre finds them and attacks. In the ensuing fight, Ogre outmatches Jin. The exact result of the battle is unknown, but Jin is knocked out cold and awakens later on to find his home destroyed and Ogre and Jun nowhere to be found. Assuming Ogre has taken Jun's life, Jin swears revenge on the Alien.

As bait to lure Ogre into the open, Heihachi announces the King of Iron Fist Tournament 3 five years later. Indeed, Ogre shows up and is defeated by Paul Phoenix. However, unknown to Paul, Ogre morphs into its true form and the tournament continues. Ogre eventually confronts Jin and they clash in battle. Jin emerges victorious and Ogre is defeated.

Ending Description, "Awakening": Ogre stands on top of the burning temple and morphs into True Ogre. Two helicopters fly towards the temple but True Ogre destroys both of them with a single fire breath.

Tekken 4
Though Ogre does not appear, it plays a role in the story. Heihachi's scientists capture samples of Ogre's blood and tissue in order to splice Ogre's DNA with Heihachi's and make Heihachi immortal, but the experiment fails since Heihachi lacks the necessary Devil Gene in his blood. Heihachi announces the King of Iron Fist Tournament 4 in order to lure Kazuya and Jin, who both carry the Devil Gene, into the open.

Tekken 5
Ogre appears only in the mini-game, Devil Within, as a boss.

The plot details events that occur during the two month period between Tekken 4 and Tekken 5. After Jin leaves the Hon-Maru after the final battle in the King of Iron Fist Tournament 4, he hears rumours that his mother, Jun, is still alive at G Corporation. When Jin travels to their labs, he finds no trace of his mother, but instead discovers that G Corporation has either resurrected Ogre or found another one. In the ruins of an ancient temple beneath the labs, Jin battles Ogre once again. Ogre flees to a deeper part of the ruins with Jin in hot pursuit.

In the deeper ruins, Jin encounters a giant contraption that uses a large white orb to attack. After Jin destroys this, it is revealed that he has unwittingly broken the seal containing Ogre.

Jin battles True Ogre once again. Once it is defeated, it reveals yet another transformation. Despite its new advantages, Jin still triumphs, and destroys Ogre once and for all.

It is still debated whether the events in Devil Within are canon or not but it is generaly assumed not.