Triggerfish

The Triggerfish holiday in the United Empire of Earth (UEE) is held annually on April 1st. It is observed by playing pranks and jokes on others.

History
A holiday of hoaxes has history among humans all the way back to the 16th century, however it took on the name Triggerfish in the 2600s, when residents of Borea (Magnus II) began to try and convince visitors to the system of a secret fourth planet named "Triggerfish." More insidiously some outlaws would give unsuspecting victims coordinates to the non-existent planet only to ambush them. Due to rise of this related crime, the UEE launched an information campaign refuting that Triggerfish existed, this spread name of outside the system of origin. Eventually, Triggerfish became a slang term for a gullible person, and later the most common way to refer to the holiday.

Traditions
Participants often play pranks and participate in hoaxes on others, commonly shouting "Triggerfish!" once the hoax is completed.