Consider the Botfly
Mark W. Moffett, a.k.a. Doctor Bugs, sent in this video of a botfly emerging from under his skin. A mosquito deposited the egg into the entomologist during a recent trip to Belize. The egg hatched and grew—dining on Moffett's flesh all the way home—before emerging in front of a crowd at Harvard.
It's a short video packed with grossness, the requisite accompanying scientific humor, and of course, an explanation of the botfly's life cycle.