Divinity War Worlds: Rodor
Rodorians are the largest of all known intelligent races. Typical adults weigh two and half tons and grow to over twelve feet high. Rodorian giantism is likely due to a combination of the planet's extreme 35 degree tilt and its high concentration of CO2 in the atmosphere.
Rodorians are consummate survivors, able to improvise with objects at hand to rapidly create weapons, traps, bridges, shelters and complex machine rigging. In a contest against any other race, including humans with heavy equipment, Rodorians can build bigger and faster.
While their social structure is relatively simple, the planet-wide games of skill and strength that occur every Rodorian year (36 Earth months) are the greatest sporting spectacle in the known universe. From extreme sports to contests of man versus beast, team strategy events and mock battles with sophisticated rules and rapid changes in score, Rodorian sports are nothing but pure adrenaline. A key adaptation is the ligament network that suspends Rodorian brains inside their skull. Like rams that butt heads, giants don't suffer from concussions.
Giantism in mammals and reptiles occur oppositely. Mammals grow large in cold climates, to conserve body heat. Reptiles grow large in hot climates driven by high CO2 levels feeding the growth of massive vegetation. Rodor has both.
Due to the high angle of Rodor's tilt about about its rotational axis, regions suffer extreme seasonal changes in temperature which spur massive animal migrations. During the epic seasonal migration to follow the warmth, survival comes down to a matter of big, bigger and biggest. No matter how big their enemy, nothing can match the Rodorians combination of strength, speed, improvisation and tactics.
The hard life on Rodor made ASP interstellar commerce contracts highly attractive. With access to technology, the giants rapidly moved from subsistence living in isolated communities to safe and secure cities and jobs ranging from mining and agriculture to spaceship construction. By the time Believers reached Rodor, the planet had already been inoculated against their beliefs.
While Believers made in-roads in some of the outer communities, the climate on Rodor rapidly turned to persecution. The high council ordered a complete withdrawal of Believer security forces from Rodor and a retreat to Avalon. The closing days of the Believer retreat from Rodor minted a new generation of battle heroes, including a legendary Rodorian squad "The Juggernauts" who fought alongside a squad of human marines to defend the last garrison from an all-out military assault.
Whether friend of foe, there is no denying the effectiveness of Rodorians in modern combat. In the words of Jet Naman, a sniper on the last marine squad on Rodor, "The amount of firepower Rodorians can carry is ridiculous. They're like walking tanks."