Mad Mod possessed a ruby handled cane which he kept with himself at all times. In "Mad Mod", Moddie used the cane for several purposes such as opening doors and frustrating Robin in a few ways. (When Robin was running up stairs, Mod pressed the ruby button and made the stairs into an escalator that was going down.) Mod was also able to twirl the cane a lot, without dropping it.
In "Revolution" Mad Mod used it to drain the youth from Robin, making him old and Moddie younger. Eventually, Robin reversed the effects and then broke it, ending King Moddie the First's reign over the city. Somehow, Mad Mod repaired the cane, and it reappeared after he was initiated into the Brotherhood of Evil.
The cane also seems to grant Mad Mod transforming abilities, and this is shown clearly in the episode "Revolution", where he constantly switches his appearance. This however may be more of his illusion technology built into it.