Perhaps not anatomically correct, I didn't look up anything for reference, I just started drawing. This is my first real attempt at an animal TF (Or... 'non-human', anyway) I'm mostly interested in TG and BE, and not terribly interested in most common animal TF. But I do like uncommon stuff (insect, plant, some reptile), perhaps mostly because they're so different. The most common TFs we see tend to involve other mammals, I like to see something less similar to a human.
As for the panties, as I said before, it was really just to make it easy on myself. If you REALLY want an explanation, I dunno, they ripped at the back but got caught on something on each side.