Phantasmagoria.

An optical effect in which figures on a screen change size and shape. Related to phantasm. The last part has nothing to do with "gory". The word was coined in 1802 by an exhibitor of optical illusions in London. His name was Baron Philipstal and he had a "magic lantern" which produced special effects on a screen which were then considered marvelous. The final part of the word is based on the Greek verb ageirein (to gather or to assemble).

Source: NTC Dictionary of Word Origins, Adrian Room.