You will note that the figure still has his inappropriately placed tongue. But, the yellow eyes are far more pronounced on this version than on the later paint job. The weapon is also cast in gold plastic rather than the black from 2001. In general, this figure appears angrier than the 2001 release. But, I think the 2001 paint job is actually better. It looks more like a snake and the darker eyes give the beast a more plausible appearance in his non-transformed state. If you're going to repaint something, I'd always prefer the repaint be an upgrade over the original. And, in this case, I think it is.
Here you can see the Manimal cards.
You'll note that Manimals are not only part of Star Brigade, but also part of the Lunaritx Empire. This ties them more closely with Carcass, Lobotomaxx and Predacon. (You'll note that this figure's color scheme is also very similar to the Mexican Predacon's.)
The cardback shows off just the Manimals with cross sells of the new Power Fighters and the then pegwarming Armor Bot from 1993. Another noteworthy item is that Slythor is number 44 in the planned releases of 1994 Joes. However, the second wave of Star Brigade figures that were released in 1994 begin their numbering at 49: after the Manimals. So, the Manimals were planned for release within the Star Brigade window. Why they were cancelled when the wave of Lunartix aliens who were planned after them made it out is anybody's guess. You will also note that the Manimals were made in Indonesia as Hasbro sought ways to further cut costs on a dying line.