How to react to this

I propose this. You send him/her the original saying that he/she blatantly ripped off your work and that you wish to have it taken down. It is not an exact copy, but the face is the only thing that is not the same. Mind you, there are pictures of Tinkerbell in the same position in Peter Pan I think. Perhaps you are both taking the idea of Tinkerbell and plagarizing that. Who knows. I don't think these drawings are anything other than coincidences nor do I think they are worth any amount of money. So just say what's on your mind and get it off your mind. Also, I suggest you use the following picture to show your disgust:

 Spoiler