Pulled this one on my Mom a few years ago.......
I had just started driving truck in the oil patch. I phoned her up, told her that I had been a tip-over accident. That I was hauling fuel, and it lit on fire and spread to an open grassland, and the raging inferno was rapidly approaching a multi-billion dollar processing plant. She asked if I was alright, I said yes but I played it out for a little bit.
She's freaking out.....my Dad's in the background like "whats going on ?"
Finally she asks me sternly, what happened. I tell her " Well I woke up late to start my run, so I was in a hurry, speeding and as I approached a corner, I looked down at my cell phone........and I saw it was April Fools Day !!!!!"
She flipped out.....then tells my Dad cause he's wondering WTF. I can hear her telling him, then it was silent for a second then I hear him bust out laughing.
She was a little choked with me for that one for a while.