The Tyannans was the only indigenous intelligent lifeform in the extra dimensional realm known as the Negative Zone. The apeared to be humanoid like lion-people, with fur covering their body and long mains around their heads.
The Tyannans were already a really advanced, and were proud and arrogant about their achivements, and tried to reach the heights declined in other species. They built huge factories that produce the seeds of life and living spores in sealed gold power boats, so they can survive a journey to the seed of stars. They explore the Negative Zone to the utmost limits, mapping worlds in which it seemed capable of supporting life. One of the first planets were scattered Baluur which later became the home to the Blastaar one of the Fantastic Four’s Enemies.
However, the collision of a meteorite a crippled the seeding vessels, which accidentally fell into a barren planet of Arthros in the heart of the Negative Zone, marooned the crew on the volcanic surface. Even the food processors have been destroyed in an accident, and as there was nothing edible on this barren world, the crew knew that the end was near. The Captain of the mission, decided as a last action for his crew to seed of life by releasing the spores. The Captain then dictated his crews mission to the ships record, and explains how he watched helplessly as his team began to fall around him, and starve to death soon after.
After an overreaction to the accident, which was the first failure of the dawn of time Tyannans chose to commit racial suicide. The entire population got into the vortex, in anticipation of the immanent destruction. The race instead learned they could alter their physical form into anti-matter. Out of curiosity, the Tyannans technology allowed them to do this. For Millennia, were unknown, while the entire cultures have lived and died in the remaining area.
After many million of years a lone Arthrosian insectoid creature evolved from lower life spores. The insectoid creature discovers the empty Tyannan ship. From the ships records and knowledge, the being become Annihilus as he learned of the fate of his creattors "the legacy of one race and its futile arrogance." The insectoid advanced in development fast, and once mastered the technology is in the ship he used the technology to create a powerful device that will later be known as the the Cosmic Control Rod. It also approved the transmutation of the gene that turns people found in the trash. 
Meanwhile, the surviving Tyannans took the disaster of their mission as a sign of weakness and attempted to commit global suicide by driving their planet into the center of the Annihilation Filed, the center of the Negative Zone where positive and negative matter meet and annihilate each other. Realizing that they could actually phase themselves and travel into the heart of the Annihilation Field, the Tyannans' own scientific curiosity took hold and they instead decided to exile themselves from the Zone entirely. Within the center of the Field, the Tyannans lived on undisturbed for quite some time. 
Untold years later during the modern age, the Brute an duplicate of the Fantastic Four's Mister Fantastic from Counter-Earth was trapped in Zone after retrieving the Cosmic Control Rod and returning it to Annihilus. . Floating near the Negative Zone's Distortion Area, where, instead of being destroyed, he was rescued by the Tyannans. His evil ways returning, Richards tried to control the Tyannans and attempted to take over the Negative Zone and open a portal between the positive and negative matter universes.
Reed developed a new generator for converting Tyannans negative energy into positive, so he could escape the vortex. The generator is activated, a pulse of energy emitted into the vortex. One was identified by beings of power, as Blastar and his chief rival Annihilus, who tried to investigate, and use it for their own plans of conquest. The pulse also attracted the attention of the Fantastic Four, who went to investigate it's potential threat to both the positive and negative universes. After a clash between all three parties, they entered into an uneasy alliance in order to investigate the energy of the pulse within the vortex. All were quickly conquered by the Tyannans, under the control of the evil Reed Richards from Counter-Earth. Seeking to conquer both the positive and anti-matter universes, the evil Richards then he took them to escape to attack Blastaar's homeworld of Baluur, planning to obliterate the planet. Brute then prepared to lead the Tyannans against Earth. The Fantastic Four and their erstwhile allies soon broke free and battle Brute and his army. All the while the Tyannans tried to destroy the barrier between universes. However, Mister Fantastic had theorized that the energy field that protected the Tyannans in the Negative Zone only worked for a limited time, so the attack delayed things long enough for the fields to wear off and the Tyannans to be shunted back to their home in the vortex.
With the Brute's plans shattered, Annihilus and Blastaar then attempted to breach the barrier alone. However by this point the damage had been done and threatened to destroy both realities. Following their return home, the Tyannans were freed from the control of the Brute and they had created a means of sealing the breach between dimensions, but needed a powerful mind to channel their device through. Mister Fantastic risked his mind in order to do so and the breach between the positive and anti-matter universes were sealed. Not seeking to be taken advantage of again, the Tyannans then sealed their home away in the Annihilation Field in order to prevent intruders from their domain again. The resulting explosion destroyed the Brute's ship, and while the Fantastic Four seemingly escaped, the Brute was seemingly slain. 
Type of Government: Democratic
Level of Technology: Advanced Space faring Race
Cultural Traits: Tyannans as a people are dedicated to peace and progression of life. In the past, they were naively trusting, but their experiences with the Brute likely resolved this. The culture as been described as being arrogant, but that was likely just an overly critical observation based on their failed mission which had doomed the crew of one ship.
- Stats per FF Fifty Fantastic Years #1.
- Discuss Tyannans on the forums
- Appearances of Tyannans
- Minor Appearances of Tyannans
- Media Tyannans was Mentioned in
- Race Gallery: Tyannans
- Images of Tyannans