Psycho Crawler

The Psycho Crawler is a very annoying NPC to deal with, for it's high speed and swarm capability. Psycho Crawlers spawn on Wave 14+, and on that specific wave, they spawn on a higher rate than other enemies. Regular Zombies have a 5-stud height, but Psycho Crawlers have about a 2-stud height, making them not only hard to shoot, but also hard to detect in swarms.