The Tantaror were first seen to visit Mobius in early 1996. Three "heretics" entered the planet on the Ghost Ship of Tantaragor and immediately found themselves some Mobian slaves. The aliens were followers of evil priest Orkym-Ro and believed that they needed to build a massive monument to ease his passage into the afterlife.
Somehow, Captain Plunder and the Sky Pirates learned of the ghost ship and pursued it. Eventually, they discovered it hiding in the clouds but a freak boltof lightning destroyed their ship's mast and sent them crashing down to the Floating Island. With help from Knuckles the Echidna, the pirates were raised back up the ship and stowed away, only to find the Mobian slaves. They also discovered the Tantaragor Idol, which helped them escape from the Tantaror.
Later, the idol was operated by Ekkletos, taking the pirates and Knuckles to the Tantaror dimension. Knuckles explained the situation and volunteered to rescue the slaves from the rebels. The echidna took a beating, but his presence was just a distraction for Ekkletos to summon the entire ship to their dimension.
Over a year later, Sonic the Hedgehog and Tails became lost whilst on the biplane and it soon became apparent that they were somehow in another dimension. Attempting to get their heads around things, obstacles kept cropping up (mazes, a minotaur, a herd of yetis) as soon as Tails thought of them. Sonic deduced that someone was listening to them and called out for the source of the trouble. A Tantaror youth appeared and demanded that the Mobians continue to do his bidding. Before Sonic needed to get his hands dirty, the Tantaror's father appeared and berated his son for "keeping pets". Sonic objected, but the heroes were returned to the Emerald Hill Zone.