Oboe

The OBOE is an item in Problem Sleuth. Though it could have easily been added to anyone's inventory, nobody bothered to actually pick it up.

The OBOE was initially found in the Speakeasy, wedged between the Still Room and Piano Room doors. This meant neither door could be opened from within. The amount of Vim required to remove the OBOE is somewhere between that of Pickle Inspector and Fiesta Ace Dick.

The OBOE was eventually removed when PI solved some weird puzzle shit. However, in an alternate non-canon reality, it was replaced by ten BASOONS.