Cranky Kong

Cranky Kong is a character from the Donkey Kong games. He was created by Rare and is owned by Nintendo. Cranky was introduced in Donkey Kong Country and was said to be Donkey Kong's grandfather. He is an elderly version of the original Donkey Kong from the arcade game. He is known for complaining about the games of today and how older games are superior.

Donkey Kong (Arcade Game)
Cranky was the original Donkey Kong from the arcade game. He captured Pauline and tries to stop Jumpman (Mario) from saving her.

Donkey Kong Country
Cranky in this game is an elderly ape who gives you hints about the game and often rants about how older games are more superior. Cranky also gives Donkey Kong and Diddy Kong whacks with his cane. Cranky also comments about how bad the game is in the instruction manual for the game.

Donkey Kong Country 2
Cranky played a similar role, but this time you had to pay him Banana Coins for his advice with free insults. In the Game Boy Advance version, he hosted Expresso Racing.

Donkey Kong Country 3: Dixie Kong's Double Trouble!
Cranky, instead of giving advice, plays as your opponent in Swanky's bonus games.

Donkey Kong 64
Cranky turned into a mad scientist and made potions for the five Kongs to buy necessary to beat the game. He also owned the Rareware game Jetpac that you could play after earning 15 Banana Medals. When you score 5,000 points, you get the Rareware Coin necessary to beat the game.

DK: King of Swing
Cranky taught players how to play the game, along with Wrinkly Kong.

Donkey Kong Country Returns
Cranky actually seemed much less critical in this game as he doesn't insult the player at all. In this game he owned a shop where players could buy lives, power-ups, and even Squawks the Parrot to aid them on their journey with the use of Banana Coins.

Theory
As described above Cranky Kong may be the original Donkey Kong from the arcade game of the same name, however this would mean that Donkey Kong Jr. is Donkey Kong's father since Cranky is the grandfather of DK.