The Turtles are the main mode of transportation of Big Green. They have treads underneath them so they can move at a fast pace. As seen in the episode "Shark Castle", the turtles were once customized by Lin Chung, although this was an accident.
Turtles are fiercly loyal to each other, and will not hesitate to seek vengence upon those who make one of their own cry. Whenever a turtle cries it has the ability to send that tear all the way back to Big Green regardless of how many miles they are from it. When the tear reaches Big Green the entire Turtle army mobilises to the location within seconds, fully armed and ready to blast whoever caused the tear with cannon fire.
It is known that at least some turtles can speak human language. There is some suggestion, such as Mighty Ray's discourse with his turtle in "Rhino Castle", that this is not uncommon amongst the turtles, but only Mighty Ray's turtle , Lin Chung's turtle and Turtle King have actually demonstrated it.