A prank involving sending someone out to get a non-existent item. Typical items include:
In college, this was a popular prank to pull on fraternity pledges. The were sent to another house whose members will recognize that prank in progress and will send to victim to yet another house with the goal seeing how many houses will be queried
A colleague worked in an engineering establishment where new employees were asked to fetch a piece of equipment that was a 10 foot or so construction of connected tubes. It had no practical use - but it was near impossible to navigate between the store room and the labs, so the newbie would be left to struggle with the unwieldy thing while everyone else collapsed in giggles...
One particular schoolteacher I remember used to send troublesome students to another teacher for a "long stand" (and tartan paint). They were invariably told by the second teacher to stay put for a moment, whereupon they were left with that which they came for.
a similar one to that is the long weight
Why sleeveless?