The Donkey Kong (ドンキーコング Donkī Kongu) universe refers to the Super Smash Flash series' of characters, stages, and properties that hail from the sub-franchise of the famous Mario series that deals with the character Donkey Kong. It is generally agreed on that Donkey Kong and related items count as Mario properties, but DK has appeared in enough of his own games alongside enough original characters, created by second-party developer Rareware instead of Nintendo itself, that many consider him as holding sway over a "sub-universe" of Mario. Donkey Kong is also considered part of his own universe because his smasher's icon consists of the letters DK rather than the iconic image of a Super Mushroom held by other Mario characters.