In the distance, you can spot a man walking across the beach. He has not seen you yet, so you decide to draw his attention by singing softly, but audible. After a few moments, he picks up your siren song and slowly turns his head to see where the sound is coming from. You then manage to make eye contact and you say:"hi, out for a stroll on the beach?" "Um, yes", he stammers, but you have your reply ready:"want to come join me in my sunbathing?" His head turns slightly red, and without answering he starts wading through the water towards you and as he is close enough you say:"now, let me get to the point of what this is all about. Make yourself comfortable, and choose..." You slowly lift your translucently-finned tail out of the water and lay down on the rock. "A...a mermaid?!", he reacts with surprise. "Yes, don't worry", you say, "I'm here to make you an offer." You show him the stone and starfish and say:"Choose the starfish, and you will join me as my mate, a merman. Choose the stone if you do not want such beauty..."
The man thinks a moment and says:"Rather not. A kind offer, but no thanks." He then picks the stone and your smile turns to a grimace. "Fool! If you will not have the beauty of the merfolk, you shall have ugliness!" You activate the transformation stone, and it glows in his hand. You do consider, however, if you turn him into a frog he might join the other side, but it's so tempting to just watch him inflate into a bug-eyed slimeball...actually, you have a lot of ideas of what you could do to punish his pride.