Not sure how much this applies to this particular thread, since this is a Gen 4 Pokemon, but I noticed that there are no Moemon sprites for Burmy at all. So, I decided to make it myself.
I used the head from a Litwick sprite I found, along with the original Burmy sprite and legs from Zoura and Dragonair Moemons. I tried to create a version with the stalk as well. Works fine for the front sprites, but the back sprites end up way too tall, even after shortening the stalk.