Moss first met Mighty and Ray the Flying Squirrel during the Shattered World Crisis, when Mighty was struggling with his temper and his inability to do more for victims of the catastrophe. The Sloth helped the Armadillo to come to terms with his limitations, and helped Mighty find the drive to do more for the world. Ray also benefited from Moss' lessons, and the two friends later introduced Moss to Sonic the Hedgehog, Sally Acorn, and Amy Rose of the Knothole Freedom Fighters after finding them in the Rocky Jungle Zone. Moss quickly sensed the corrupting influence of Dark Gaia within Sonic, but remained behind as the Freedom Fighters, Mighty, and Ray left in search of a Chaos Emerald. After Sonic became the Werehog but was calmed down by his friends, Moss welcomed them back into his hut, and predicted Sonic's transformation back into his normal form upon the sun's rising. Fearing the harm he might do were he to transform again and lose control, Sonic submitted himself to Moss' tutelage in hopes of mastering his new form. (StH: #263, #264, #265)
Moss and Sonic competed against each other in races through the jungle, during which Moss did his best to impart to Sonic the need for acceptance rather than control. He stressed that the Werehog was part of Sonic, and that once he stopped fighting it he would no longer be consumed by it. Mighty and Ray contributed their insight as well, and Sonic was so impressed by Mighty's new-found maturity that he suggested that Mighty would do well leading a group of Freedom Fighters. Ray and Moss also liked the idea, and Moss even suggested that some former students of his might benefit from Mighty's guidance. At nightfall, Sonic transformed again, but thanks to Moss' counsel retained control of himself. The group was then attacked by a Flying Dynamo sent by Thunderbolt the Chinchilla, but Moss' students worked together to dispatch it. His training complete, Sonic left Moss and rejoined his teammates aboard the Sky Patrol. (StH: #266, #267)
Sloth, Mighty, and Ray later helped Amy and Knuckles retrieve the pieces of the Master Emerald.
Moss is typically a very laid back, zen-master individual, filled with wisdom and eager to impart it. He is quick to emphasize to his students the fact that there are things in life that must be accepted, for it is beyond their power to change them at present.
Moss the Sloth is an sloth that is mostly covered in jungle green fur. He has a white face with black patches around his eyes and a white beard that falls down to the end of his torso. He also has black palms with long white fingers, and wears black-colored "boots" on his feet, with his actual feet being colored white.
Despite his species, Moss is actually quite agile, moving swiftly and surely through his jungle home with a knowledge that gives him an edge nearly as great as Sonic's super speed. He also appears to possess strong emphatic abilities, as shown by his discernment of Mighty's drive and the presence of Dark Gaia's evil within Sonic.
- Moss' name and coloration references real-world sloths as their bodies make good habitats for other organisms. One such organism is green algae, which can make them appear green.