Phantasmagoric- the process of a constantly shifting complex succession of things seen or imagined. Its noun is phantasmagoria- a scene that constantly changes or fluctuates.
“That evening occurred a crisis of nerves in the German camp, precipitated by two phantasmagoric intelligence reports: a great body of enemy calvary was in movement to the south and coming around Francois’s flank; and, out of Rennenkampf’s army, one corps was advancing on Mackensen’s rear.”
-S.L.A. Marshall, World War I (1964)