My kids found a video at PBS kids a few months ago that they found hilarious. The tune is catchy, fun, and well, about poop. On the plus side, there are lots of great vocabulary words (omnivore, carnivore, etc.). On the negative side, well, most of them are synonyms for poop (skat, feces, etc.).
I'm not sure whether I should admit it or not, but the lyrics have entered our family's lexicon. Nowadays, whenever someone says, "Guess what?" someone else is likely to chime in with "Every dinosaur poops?" no matter what the first person was going to say.
So, in an attempt to spread around the hilarity and misery, I encourage you to check out the video for yourself. Let your kids listen to it half a hundred times or so and I'm sure your family will have as much fun with it as mine has.