Plague Crawler is a file that can be found in Resident Evil: The Darkside Chronicles.
This file is unlocked after beating "Operation Javier 3" on Normal.
Insect-based B.O.W.s that were created by injecting various types of insects with the T-Virus and then manipulating their genes. Some are almost 2 meters long and have suitably large death-dealing pincers. They lack the intelligence to be suitable for use on the battlefield, so their development was halted and they were to be destroyed. However, some of them escaped destruction and were purchased by Javier as low-cost B.O.W.s.