Wikipedia
Gyckel, jyckel, also known as spex on some University faculties (not to be confused with the theatre form Spex), is short theatrical appearance performed at a Gask. A gyckel often involves a group of students singing a song or playing a play lasting no more than a few minutes. There are several unwritten rules, the most important one is that the jyckel must be written by the performers and be presented for the first time at the gask. The gyckel should also be sarcastic, sexistic or humoristic.
At a gask with members from different faculties it is usually expected that each faculty perform its own gyckel. Others may also report that they will be performing a gyckel to the toastmaster. The toastmaster announced when the time has come for a certain group to perform their gyckel.