They may look peaceful in this gauzy digital simulation, but parasitic wasp embryos inspired the infamous "birth" scene in the 1979 horror flick Alien. Injected into a caterpillar by their mother, the once egg-encased wasp embryos develop for about 14 days. Then things get ugly.
In a biological attack unique in the animal world, the unassuming embryos use a virus in their DNA to paralyze their host. They bite their way out of the caterpillar and begin spinning cocoons.
As a final insult to the injured host, the caterpillar--apparently brain-addled by the virus--builds a silky blanket over its attackers and defends them against predators until the wasps emerge, fully formed, and take to the skies.