Zombies. Clint thought it was all a bad joke until that Daisy chick showed him pictures and videos of the last time there had been a portal to zombie land. And the things with the chickens and the snowmen. So he was trying to take it a bit more seriously. This was why he had paid close attention to where he was walking, and who was nearby when he headed to the gas station to pick up some more snacks. He had thought the cashier would think he was casing the place the way he kept looking around, but she had barely looked up from her phone.
It was when he stepped foot in the front yard that he screwed up. Instead of staying on the sidewalk, he'd cut through the front yard and stepped on an early dandelion plant that was hiding a few of the cordyceps underneath. He probably would have been okay when the puff of spores surrounded his foot, but he had chosen to wear shorts, and the spores settled on his skin quickly.
Clint did what any reasonable teenager would do in his situation; he stood very still and yelled as loud as he could for Phil.