The wasps of the genus Glyptapanteles :
These sadistik animals injects ther eggs into a living caterpillar were they will hatch and feed on the caterpillar fluids gradualy getting bigger and being carfull not to touch her internal organs to keep her alive ( you will later know why) so the catarpilar keeps her normal life with the exeption of those little parasites growing inaide of her when they are ready to get out they just kinda chew ther way out just imagine about 80 of those emerging from her body but despite that she dosn't die
yes her agony is not over yet as she is brainwashed by them to first use her silk to cover ther cacoons giving them extra protection and then she stands guard protecting them from dangers (and that's why they kept her alive)
until she eventualy dies from starvation when they have matured and emerged from ther cacoons.