Thrax's Origins

[Delta Black]

Could Thrax have just been a powerful monster Rita and Zedd created that came to think they were his parents?

[MattEmily]

highly unlikely but I suppose it's possible.

[Starlight Starbrite]

I think that's pretty likely. It would make more sense than him being their biological son. Of course it doesn't explain why he was trapped in a dumpster a million years before he could have been born.

[Dino Charger]

Thrax just aged quicker than a normal child. He also went back in time a million years and fought Sentinnal Knight.

[Gosei Gold]

Well if you want to use time travel, Thrax could have been from any point in the future. So You don't have to say he aged quicker.

[Phantom Stranger]

Thrax was from the SPD era. That's why Bridge was so easily accessible in "Once A Ranger. "
He was already on a mission to arrest Thrax.

[Usagi Reborn]

The character was just too poorly thought out. He was the son of Rita and Zedd as a gimmick for "Once A Ranger". They didn't bother givening him a back story that made sense with who he is supposed to be.