This addon adds 14 new hostile mobs that evolve and combine over time. You have to defeat them before they evolve into stronger parasites. They come in 4 stages, the buglin, the infected mobs, and the fully evolved parasites.
Mobs
buglin - spawns in dark, evolves into rupter after a minute
rupter - infects passive mobs evolves into a random beast after 2 minutes
infected mobs - infects passive mobs evolves into a random beast after 2 minutes
random beast (5 total) - powerful enemies that infect mobs and kill the player
Weapons
pickaxe - mines fast, craftable
scythe - kills fast, gives speed, craftable
bow - shoots projectiles that infect and kill mobs, craftable
each hostile mob comes in 5 random sizes, the larger the mob is the more powerful it is.