Kid Kirby was meant to be a “prequel” of the series, a platform game with a younger Kirby (with hair?) that was in development at DMA Design, the makers of Uniracers, Silicon Valley and Lemmings. A little image from this game was already seen in an old magazine, but only recently we found more concepts from the project, thanks to a flickr account from an ex-DMA developer. From an article on Gamasutra we read that Kid Kirby “was to be a showcase for the SNES mouse, but the mouse did not sell that well and the game was not great when played with a joypad, so it never saw the light of day”.
Additional Kid Kirby renders were discovered on a 1995 Nintendo Source Book binder intended for retailers. These pictures were taken by Tomato and Heidi Poe of Earthbound Central.
You can find more about the Kirby series in the WiKirby!