Espio in Chaotix always did look more like a Dinosaur than a chameleon to me. If it wasn't for the palette cycling and the label of "X the Animal" it wouldn't have even occurred to me that he was one. It makes total sense that they'd want to reuse the design. Maybe, given the existence of less refined Vector sprites with slightly less colours presumably from some point in Crackers' MD development, work had already started on Espio sprites prior to any implementation on the 32x. Maybe Espio was even considered for a solo game after S&K prior to rolling him into the Crackers experiment, and thus his starring role was still in mind prior to re-leading the game as a Knuckles venture. It would be curious to get in contact with the guy behind the Crackers engine experiment (Hiroshi Okamoto) to hear more about it's development. It's clear that they weren't building off of the Naka engine but trying their best to replicate it, so I wonder what led to that weird break and need to replicate an engine. We do know that Naka was later proprietary about his engines in X-Treme's development. Were SEGA trying to remove their reliance on Naka for company politic reasons? Was Crackers an offshoot of an attempt to replace Naka which failed and thus became a weird grab bag of Sonic-esque stuff? Okamoto's first project for the Sega CD "Panic!" did release in 1993, and his next work was Chief Programmer of Chaotix. He worked sporadically for them since then.