An extension accessory for the Nintendo 3DS is about to be revealed at the forthcoming Tokyo Game Show, and it makes the current handheld console look more like the original beefy DS.

Translated from Japanese as "Extension Slide Pad" (or "Kakuchou Slide Pad"), the device houses the base of the 3DS and, at the very least, adds an extra thumbstick on the right hand side.

Pictures of the Slide Pad have appeared in top Japanese games magazine Weekly Famitsu (which was scanned by Twitter user @south1996), featuring alongside an interview with Monster Hunter series supervisor Ryozo Tsujimoto about the forthcoming addition to the franchise, Monster Hunter 3G. Clearly, the accessory works with that specific game, but it's unclear at present exactly how.

Tsujimoto has said, however, that the Slide Pad provides a good grip on the system, and website reveals that he also sees the expansion as a "secret weapon", allowing the latest game to play and feel more like the Wii version.

Nintendo is holding a press conference next week before TGS starts, so expect to find out more then.

What do you think the mystery Slide Pad will be capable of? Let us know in the comments below...