Mirage

Mirages are translucent objects that appear in the sky in the desert after staying in one for 4 hours.

Mechanics
A mirage can choose randomly from any block or decorative object and cause a translucent clone of it to float randomly in the sky. This clone is not physical. More mirages form as you stay in the desert longer. Mirages will fade at nighttime and when you enter any non-snow or desert biome.

The purpose of mirages is to confuse the player while they are in the desert.