The Royal Albert Hall organ has a bass drum stop! You can see it on the specification (https://en.wikipedia.org/wiki/Royal_Albert_Hall_Organ).
I heard that originally the power of the vibrations created were such that they had to dampen the organ to avoid structural damage, however I can't find evidence to support this.
The organ at Ripon Cathedral has a wooden hand mechanism so the organist can conduct the choir whilst playing.
Almost all organists have a story of when an organ builder/repairer/tuner has left something behind - such as a ladder, which can cause significant rattling.
Organs continually compete to be the 'largest in the world' - usually by adding just a few stops.