Robert's wish was spreading, or more correctly other beliefs he held were also coming true. He knew that Katie Blackwitch was a witch, but now his faint belief she could perform real magic was reality.
Thus when he considered Gloria, Fred and Ralph blood-sucking leeches who delighted in causing others pain, he really made them the closest thing to that, perhaps influenced by his interest in werewolves. Vampires.
Of course the trio didn't know this any more Robert did, but they knew something had happened and that they were radically different than before. Their skin had gone pain and it hurt to be out in the sun was a fairly big clue.
They were blessed or perhaps cursed with instrincts that matched their new forms. They were agnry and thought of themselves before, but now that was greatly enhanced to the point of being predatory. They could sense their kind, which was how three that knew of each ohter but didn't actively know the others met up in a disused storage room at school.
For what ever reason, Gloria seemed to take charge. "You both feel it? The hole in your stomach, like you haven't eaten in days?" They all nodded. They quickly noticed their new fangs, but hadn't linked everything together yet.
They reached out and touched each other's ears, noticed their hair had gone a shade or so darker and grown longer, but the boys focused on the fact Gloria's breasts appeared to have gone up at least a cup size or two and her bra was straining to contain them.
Gloria of course in turn noticed that Fred and Ralph were, even when only partially errect, also sporting enhancements to their sexual organs. Before she had transformed Gloria had used her body to get want she wanted. She undid her shirt, and let her bra fall away. She kneaded her breasts and cooed. "How about we see what our new bodies can do..."
The boys chucked as they unzipped and let their throbing members out, while Gloria hiked up her skirt and tore down her panties, revealing that her sex was wide and seeingly larger than before.
Gloria hissed as she stroked off the two boys, their cocks where more akin to white baseball bats than anything human. Then something caught her eye behind them. Or rather something she didn't see in a mirror behind them.
"I know what we're hungry for..."