Finally I'm able to get online and post. ;o
Anywho, I came up with a whole evolutionary line this time based off of one of the original design ideas but ignored in artwork, the echidna.
Well, its starts off as a pure grass typed little echidna with an innate ability to store large amounts of heat within its body.
When it evolves into his stage two form, he sprouts a couple basic prehensile leaf arms which allow him to shuffle about a bit faster. Certain parts of his fur also get set ablaze due to its body temperature.
Upon final evolution, the arms grow much longer and more powerful, and lower legs are developed, allowing for bipedal motion. Body temperature is more carefully controlled and is mainly routed to the tail and neck, causing the fur to be in a constant blaze.
Without further ado, here's the chain. First evo is in the middle, second form is to the left, and final form is on the right:
And a pick which focuses more on the final evo:
EDIT: Working on coloring the Cockatrice and final evo right now.