There wasn't anything "special" about these toys, except they were small ninjas in various colors, packed in a cool packaging with one crazy background story on the back, telling me that these actually were real ninjas who got shrinked. It didn't need more to get me hooked!
Mini Ninja came in 4, 8, and 12-packs. The artwork and background story was done by John Manders, who also did the artwork for Remco's Mini Mashers. I don't think there have been more than these 12 different ninja characters I got. Each figure was numbered. My favorite figure was #8, a guy that looked like Rambo and didn't have much of a ninja. But actually I loved all of them. Each character was unique, and kept a special place in my heart.