Splinter's cane is a walking stick that Splinter uses for his own needs, such as making it easier to walk (because of his age), aswell as using it for battle. It is green and looks to be made of a transluscent crystal. Not much is known about it, but there are some rumors going around that it may be crystalized Ooze or some kind of green stone. This has not been confirmed, however.
This is a perfect weapon for Spinter as his previous incarnations have used the cane in battle. The cane is also strong for offense and defense, representing Splinter's balance in strength and defense. It is revealed in 'Vengeance Is Mine' that it is really a sword.