Superphenomenons are extremely amazing and extraordinary events or things that are really, really special.
Superphenomenons are usually thought of as really, really cool and impressive.
Examples:
The rainbow was a superphenomenon in the sky.
The superphenomenon of the meteor shower amazed everyone.
The superphenomenon of the giant pumpkin was really, really big.
The superphenomenon of the talking animals was very, very surprising.
The superphenomenon of the dinosaur coming back to life was unbelievable.
The superphenomenon of the magic show made everyone cheer.