The Skrall were formerly soldiers in the Core War on Spherus Magna under the Element Lord of Rock. A large number of them ended up on Bara Magna after The Shattering, and settled in the northern parts of the planet and establishing a massive fortress city.
Thousands of years later, the tribe was attacked by the Baterra, shapeshifting beings who killed many Skrall including most of all the leader class Skrall. Only Tuma survived the attacks. They then moved south to avoid extinction. However they used the chaos to abandon the female Skrall who later formed their own separate tribe. The male Skrall then occupied the abandoned city of Roxtus and were later employed as Glatorians. One year later, Tuma, leader of the Skrall, ordered them to attack the Arena Magna during the Great Tournament, killing many Glatorian and Agori. Metus later convinced the Skrall and the Bone Hunters to join forces. After uniting, they destroyed Tajun, leaving its inhabitants refugees. Mata Nui entered the arena, and challenged Tuma to a fight for his friends' freedom. Tuma accepted the challenge and was eventually defeated by Mata Nui. Metus, who revealed himself as a traitor, later arrived in the city, and ordered all the Skrall and Bone Hunters to attack. Before they could launch their assault, a massive creature arose from the sands (greatly resembling Malum). The Skrall believed it to be a Baterra attack and panicked, fleeing the arena. They encountered the Glatorian, and fought them. Five of the Glatorian, who had elemental powers, were able to defeat the army.
With the defeat of Tuma, the Skrall abandoned Roxtus and began following elite soldiers. Elite Skrall (Stars) A Skrall during the Battle of Bara Magna.
When Makuta arrived on Bara Magna, he released Rahkshi and Skakdi on Bara Magna to battle the Glatorian. A few Skrall, led by Stronius, took advantage of the situation, and attacked the Glatorian for revenge.
When the Rahkshi were finally destroyed by the powers of the Golden Armor, and Teridax had been defeated by Mata Nui, the Skrall and Skakdi surrendered to the Glatorian and Toa.