Tarantula hawk

The tarantula hawk reproduces by stinging a tarantula, dragging it back to its nest, laying just one egg on the tarantula's back, covers the entrance to the said nest and when the egg hatches the larva digs into the still alive tarantula where it eats it's filled before going through a metamorphosis and bursting out of the tarantula's abdomen to resume the twisted torture again.