Warning: The following contains spoilers for Avengers #26 by Jason Aaron, Dale Keown, Andrea Sorrentino, Joe Weems, Cam Smith, Craig Yeung, Jason Keith, Erick Arciniega and Jay David Ramos
The Starbrand powers have been transferred between other beings over the eons, empowering humans with the kind of cosmic strength that makes them capable of standing up to other major universal threats. But it turns out the very first Starbrand wasn't a human at all.
Avengers #26 introduces perhaps the most surprising Starbrand of all -- an unnamed Tyrannosaur rex.
KING OF THE DINOSAURS
Taking place 66 million years before the events of the current Marvel Universe, an asteroid landed on prehistoric Earth. The fires from the blast enveloped most of the planet, wiping out a majority of the natural species in the world. But it also created the first White Event, which opened up the superflow of energy deep within the planet and allowed the powers created by the Celestials to come to the surface. Searching for a host, the power ended up bonding with a dying Tyrannosaurus rex.
This transformed the dinosaur into the Earth's earliest cosmically empowered protector, the very first version of the Starbrand. This version of the Starbrand protected the planet against the invading armies of the Kree. It was able to unleash massive energy against an army of invading aliens, presumably on the planet during the same time period in which they conducted experiments that created beings like the Inhumans.
The Starbrand T-Rex was able to survive for millions of years as the guardian of the planet, giving other species (including humanity) the chance to flourish and grow while the rest of the cosmos developed. But after millennia, the humans Vnn and Brrkk ended up falling through a special garden while being targeted by a group of Deviants. The garden had been growing larger and more potent.
In the rocks below, Vnn finds the body of his lover Brrkk -- as well as the T. Rex Starbrand. The Starbrand was underground there for an unspecified period of time, providing the kind of power that would help create the beautiful garden in the first place. While down there, Vnn is exposed to the power. As the only living being in the vicinity, he absorbs the energies and is turned into the Hulkish Starbrand, who would later join the Avengers of 1,000,000 BC.
THE BIGGEST STARBRAND EVER
In a universe predicated on absurd warriors and incalculable powers, there's something special about seeing a Tyrannosaurus rex that can shoot energy blasts whenever it roars at enemies. It's the kind of over the top power that works well within the greater Marvel Universe. With Avengers introducing the ancient guardians of the Earth from eons before the present day, revealing that there was an even more absurd protector of the planet makes perfect sense. It also shows just how determined the Kree were to take over the Earth -- and what exactly was tough enough to stop them.
This storyline further explores and expands the overall connections between corners of the disparate pieces of the Marvel Universe, finding a way to bring pieces from the Eternals and the Inhumans together. It's also just an amazing plot point in general.