Overview

"Colossus were a natural evolution on Tos'var, massive elementals that formed the lands and seas in two distinct sub-species." (Source: Discord)
"Colossus are elemental beings, and most experts agree that the element they were composed of is what made the distinction between Titan and Leviathan." (Source: Discord)

Appearance

"The Colossus are an incredibly varied species, and some scholars believe that each one is completely unique. Typically they were somewhat amorphous in form, being composed of elemental magic and fragments of the world around them. They tended to have animalistic physical traits depending on their element and subspecies. For example, one of the more famous ones was a Leviathan that resembled a massive serpent composed of an ever-burning coral reef." (Source: Discord)

"Titans ruled the land and skies." (Source: Discord)
"[The Colossus that were] more associated with the elements of earth, fire and metal. (This is far from an accurate classification, as there are examples of Titans displaying elements more common to Leviathans and vice versa.)" (Source: Discord)

"Leviathan called the seas and depths their home." (Source: Discord)
"[The Colossus that] were more related to the elements of wind, water and lightning. (This is far from an accurate classification, as there are examples of Titans displaying elements more common to Leviathans and vice versa.)" (Source: Discord)

All over Tos’var.

"It's unknown just how long the Colossus have existed on Tos'var. No real traces of their history or culture have ever been found. Most of what is known about them is derived from the races that observed them, and even that is quite small. As far as can be told, the Colossus have always been on Tos'var, and the actions that they take have shaped the world for better or worse as the conflict between the land and the depths has raged on." (Source: Discord)
"Colossus were one of the oldest and most powerful beings to ever exist on Tos'var naturally. According to scattered history, they were revered as gods in many cultures and some did respond to worship by giving assistance to those that worshiped them, usually by helping in gathering resources or shielding them from disasters." (Source: Discord)

"It is hard to say what their purpose as Worldbearers was however, as Colossus claimed portions of the world as their own to simply occupy and didn't tend to gather in large numbers or actively seek each other out. Their presence tended to change the area around them but it's unknown if this was intentional or not." (Source: Discord)
"[Colossus didn't really take care in how their battles shaped the world.] Most Colossus didn't seem to take much interest in the younger races or the damage they were causing. They didn't even seem to go about terraforming with any specific goal or end in mind, simply changing whatever was around them to better suit themselves." (Source: Discord)