Worked for an old surveyor that told the story of 'chainies' that weren't usually the sharpest tool in the shed. Standard first day prank was to send them off for a can of red and white striped paint. He had one guy with a few more neurons than most, and he realised what was up, but was happy to go out for the drive anyway. He went for a burger, came back a half hour later and said 'dammit, you forgot to tell me whether you wanted the stripes up and down or left and right...'
I listened to a podcast for a bit called 'Trickeration'. One guy told the story of how he got the dream job of a bat boy for the Yankees, and his first day. One of the hitters told him he needed a bat stretcher and asked the bat boy to find one. He got sent to about 5 different people, eventually to the opposition equipment manager who gave him $20 and sent him to the sports store to buy two - a left hand and right hand one. I don't recall if he kept the $20 or not.
But the best one I've heard was a bank employee's first day at ANZ. They sent him to the Westpac down the road to ask them for their ledger (before it was all electronic). Except the guy at Westpac he happened to ask was also a first day rookie, and assumed it was a normal request. Imagine the surprise at ANZ when he actually returned with it!