On the day of our final, my science teacher showed us some videos to relax us a bit, one of which has been stuck in my head for, like, 2 weeks now. And apparently my professor's 4-year-old loves them.
Hippo and Dog
Hippo fart annoys Dog
And last, but not least, the creepy German Gummy Bear (also comes in Spanish, French, Swedish and Slovak, but I think I like the German one the best, because German is inherently funny):
Good luck getting it out of your head if you watch it.