If you've got a spare 10 minutes this has to be the funniest prank call of all time. Darren "Whackhead" Simpson a South African radio show host calls up 'Eugene' pretending to be an acquaintance from the past saying he has an incurable bone disease and needs some of Eugene's wifes breast milk as a cure. 
https://www.youtube.com/watch?v=jcfPts7G5pY

https://www.youtube.com/watch?v=jcfPts7G5pY