July 31, 1984
Donkey Kong and Donkey Kong Jr. are featured in the crowd in the arcade game Punch-Out!!.
They reappear in the arcade Super Punch-Out!! since that game reuses the same background.
May 18, 2009
The Wii game Punch-Out!! features Donkey Kong as a secret opponent. He can be fought only in Last Stand Mode, the last mode to be unlocked in the game, but once he's beaten he can also be fought in Exibition Mode.
He fights wearing red boxing gloves with his "DK" logo on them, in the same style as his tie. Unlike most boxers, the majority of his moves are taunts, and will instead counter attack the player's attacks. Also, he's the only character not to feature a montage at the start of the match, as it instead starts directly with his introductive animation, showing a barrel falling on the ring from above, followed by some bananas and then a rope ladder is lowered down and Donkey Kong arrives on the ring by sliding down it.
As little references to the original Donkey Kong game, if the player loses Donkey Kong leaves the ring carrying Little Mac over his shoulder in the same fashion as when he kidnapped Pauline, also in one of the intermissions, Doc Louis says "Listen up, son! If you're havin' trouble... Maybe I should call my plumber! Ha ha ha!" as a reference to Mario.
Possibly as a reference to his previous appearance, Donkey Kong can also be spotted in the audience in the World Circuit stadium, used both in World Circuit and Title Defense fights.
Copyrights for both series are held by Nintendo.