las plagas

The primary infectious agent in Resident Evil 4. Ancient arthropod-like obligatory parasites that, upon infecting their hosts, become bound to their nervous system and control them. Plagas are eusocial, hierarchical organisms, with dominant species Plaga specimens exerting control over the more common submissive species. This behavior led to the creatures being revered as divine beings by a cult called "Los Iluminados", who planned to spread infection globally and dominate the world.

While they broadly resemble four-legged spiders with tails in their juvenile form (which became the symbol of the cult around them), the Plagas have varying forms and degrees of maturity, though the three most common examples of incubated Plagas that become exposed upon sufficient damage to their human hosts are the immature type (referred to as "Guadaña", or "scythe"), an agglomeration of flesh and tentacles with a sharp bone blade as a weapon, the partially mature type (or "Mandibula", "jaw"), a bulkier variation that exhibits a gaping maw with sharp teeth and vestigial limbs, and the mature type ("Araña", "spider"), a fully formed specimen resembling a large arachnid with sharp limbs and a tail, which is capable of fully exiting its former host for a brief period of time as it attempts to take over another one.