Here's a great joke to play on April Fool's: ask me to work another double shift in a row at 1:30 am. I'll agree to just about anything until my brain catches up to the conversation. Earlier in the evening, two people asked me to cover shifts that I was already scheduled for, and I agreed to work for them. Five minutes later, I remembered that I was scheduled for those shifts, and was then able to crush their dreams of seeing Whitney Houston and Rob Zombie Live at the Prince William County Drive-In Dinner Theater, so that was fun.
UPDATE: Maybe it's not a prank, the same two people just asked me to cover the same two shifts again this week. The boss has also repeated his previous request that I work those same two nights in a different capacity. This would be funny if I weren't so tired.