I really enjoyed drawing today's illustration in HTML and CSS... although I must admit that I don't know much about butterflies and probably made a ton of mistakes. For starters, I don't think monarch butterflies have that eye on their wings, but let's not get too technical.
It also has a gentle animation with the wings flapping slightly as butterflies do sometimes (or always, as I said, not an expert here :P)
Here it is the CodePen with the illustration:
Here it is the video of how it was coded: