Daily Prizes appear once a day at the end of a user's first match of the day. They give you the choice between three chests to choose. Each chest holds either an amount of Blutes, or a cosmetic item. The Daily Prize resets at midnight UTC.
The exact process which the Daily Prize chests follow is unknown. Despite many users' claims of always getting the best prize out of three, the process appears to be entirely random.
Players have reported that it's possible to get more than one prize per day. This is impossible unless it's a bug. It is, however, possible to get more than one prize per session, if one's session lasts through the rest (which is midnight UTC, but to a player not living near the time zone it may appear random).
Blute amounts that have a chance to appear in Daily Prize chests in amounts anywhere from 250 to 800.
Below is a table of all cosmetic items that have been claimed to have a chance to appear in daily prize chests, sorted by each character. Remember, if you won a cosmetic item in the daily prize and can not find it, check each other characters individual outfitters.