This page explains in detail the interactions between the Donkey Kong series and the James Bond series.
GoldenEye 007[]
Donkey Kong
James Bond
August 23, 1994
A cheat option in GoldenEye 007 is called "DK Mode", which distorts all characters' models making them with giant heads, shrunken bodies and bulky arms once activated. Aside from a visual difference, this also affects gameplay, since with the models (as well as the enemies' hitboxes) change in size, making it easier to perform headshots.
It is generally considered the easiest cheat to unlock, since it's unlocked by completing the mission "Runway" on "Agent" (the easiest) difficulty in five minutes or less.
The cheat's name comes from Donkey Kong's initials, likely because of the big arm being similar to gorilla arms. However, the big head has nothing to do with Donkey Kong.
License[]
GoldenEye 007 was developed by Rare, who also developed the Donkey Kong Country games, so they included a reference to their previous works. It's unknown if Rare actually had the right to use elements from Donkey Kong, since its copyright are only held by Nintendo, but they probably didn't need it for such a minor reference.