Dec 9th - Eldest of the Kong family revealed as the fourth playable character in Donkey Kong Country: Tropical Freeze. (nintendotoday.com)
Back on topic though, they once read out a letter from a listener who claimed to have found a fourth playable character hidden in the game, and by doing a set list of actions and then soft resetting you could access him, and he was meant to be game director Koichi Ishii. (seikens.com)
He also touches on updates to the Kong family's character models, elaborates on Dixie Kong's presence in the game, explains where the inspiration for viking invaders originated, and teases a fourth playable character that remains unannounced. (pressthebuttons.com)