You can always use Cocatrice as reference for lizard feet, and Dragon's are perfect for back frames, should you have trouble with those. You can find some aid in those two if you have no idea how to make stuff look. For the tail, Ahriman could prove usefull. As for the sprite itself, have you thought about lightening the lightest brown/skin color a bit more? It might work nicely on small view, make it clearer looking(and give that eye a bit of a more definition).
Overall, great concept, I like it!
Overall, great concept, I like it!