I caught a glimpse of a group of those things running around. I saw one that looked like Heather. Maybe it was Heather. Fuck...
Heather is a character mentioned in The Last of Us.
Heather was a student at the University of Eastern Colorado. In 2013 the Cordyceps Brain Infection outbreak reached the campus. Like many people across the United States, she became infected. An unknown student who wrote many dated events in a journal that was found by Joel 20 years later stated that they saw a group of runners around the campus, including one who looked like Heather, speculating that it was her.