Nintendo Europe has announced that Super Smash Bros. Ultimate will be going receiving a three-day event, Smashers prepare as it is Spirit collection time.
The three-day event will be beginning on December 14th and has been deemed the theme "A Spectacle to Behold!". During the running times of this event, Spirits that are wearing any form of sunglasses or glasses will be "frequenting the Spirit Board."
Players should also note that during the time of this event, beating these Spirits will grant the player extra gold. The above post also details that there will be a new event every week from now on, I'd assume they would follow the same construct as this one here. Examples would most likely include; Spirits that are wearing hats, gloves, shoes, are aliens etc etc. Since there are so many Spirits found throughout Ultimate, the possibilities for the descriptive combinational categories are a plenty.