Four-and-a-half years after Donkey Kong Country: Tropical Freeze was initially released on the Wii U, a long-hidden Metroid Easter egg has been discovered in the game.
Twitter user Shane Marchis discovered the Easter egg and uploaded a video of his findings. It shows a Metroid hatchling floating in the background of level 4-3 Amiss Abyss.
To make the Metroid appear, players must proceed through the level until they reach a particularly long underwater tunnel. After swimming through it, players need to turn around and swim backwards through the tunnel, though it will have more dangers on the return trip. After doing this, players can see the Metroid far off in the background.
Source: IGN.com Metroid Easter Egg Finally Discovered in Donkey Kong Country: Tropical Freeze