Ape Foo Young is the second episode of the Donkey Kong Country animated series, as well as the second episode of the first season.
The episode begins at Cranky's Cabin, where he is playing a song ("Cranky's Gonna Show Ya") on his organ. He then begins dancing as Kremlings sneak around his cabin. General Klump and King K. Rool even stop to watch Cranky's dancing, and laugh at him. He stops when his back gives out, and the Kremlings break in. K. Rool demands the Crystal Coconut again. Cranky attempts to oppose him, but his back gives out a second time. K. Rool then has his Kritters hang Cranky by his shirt on the statue of Donkey Kong, and he is about to take the coconut when the aforementioned ape arrives. In shock, the Kremlings hide. Donkey Kong then kicks the door in, flattening King K. Rool, and he and Diddy Kong walk in. Donkey Kong is there to get Cranky's vacuum because Candy is going to his house later, and is oblivious to the hanging Cranky. He tries to get them to notice him, but they only think he is telling them where the vacuum is. With the apes distracted, the crocodiles escape, the flattened K. Rool managing to get out on his own. Diddy finds the vacuum in the cupboard and the pair leave.
A still hung Cranky begins to complain about his age, and throws his cane against the case of the Crystal Coconut. The orb is revealed, and it projects an image of Cranky forty years younger. The two begin to talk, Cranky eventually falling off the statue, with young Cranky telling old Cranky that he is too old, so he decides to create a potion to remedy this problem. The young Cranky guides him through it, and together they create the potion they wished for, the projection disappearing and the coconut retreating into its case once it is finished. Cranky drinks it, and he almost instantly becomes forty years younger, appearing just like the projection.
Back at his house, Donkey Kong is about to activate Cranky's vacuum. However, when he does, it speeds off and drags him with it. Diddy advises him not to do anything foolish, but DK does not listen. He has control of it at first, but loses it, breaking out of his house and falling off the balcony to the ground, breaking the vacuum.
K. Rool has returned to his lair, and is telling Klump about his latest plan when Cranky breaks through the roof of the cave. K. Rool and Klump do not recognize him. He wishes to fight the pair, but he is surrounded by a group of Kritters carrying Klap-Blasters sent up by Klump. They, along with Cranky, are then sent back down.
Donkey and Diddy Kong are now returning Cranky's broken vacuum, trying to think of an excuse. They enter the cabin, but find nobody is there. They "hide" the vacuum, and afterward Donkey Kong wants a banana. He opens the fridge, and, finding no bananas, he notices the potion on the top shelf. He eventually ends up accidentally drinking the potion. Diddy, however, leaves the cabin, not noticing the potion having taken effect.
Diddy arrives at DK's house, glad for his friend that Candy has not arrived yet, and is in shock to see that a baby has entered the cabin. Diddy calls for Donkey Kong, and tries calming the baby after he gets no response. He tries calling him again, this time hearing DK's catchphrase from the baby. He then figures out that Donkey Kong is the baby; he was turned into a baby version of himself by the potion. Diddy is then in dismay when he hears Candy at the entrance to the hut. Diddy tries to stall her, but Candy thinks DK is standing her up. Diddy then explains that the elevator is broken, but she comes up anyway. Diddy once again tries to stall her, this time saying that she is going to be surprised, and she believes him. However, she sees someone rummaging through DK's stuff, and she is excited to see the baby Donkey Kong. Diddy explains this to be DK's nephew.
Meanwhile, K. Rool is watching the captured and imprisoned Cranky on a TV screen. He asks Klump who he is, though Klump recognizes nothing about him. He is complaining to himself before he asks to be set free, at that point the live video feed being cut off.
Back at Donkey Kong's house, Candy and Diddy are watching him wander around the cabin. He tries to press the elevator button, but he is having trouble. Upon mentioning his name, Candy then asks where Donkey is, and Diddy tells her that he is going to return soon. Needing to go to Cranky's cabin to get help, Diddy then tells her he needs to make a banana run for baby Donkey Kong, and asks her to watch baby DK. Candy accepts the job, telling Diddy she was going to wait for him anyway, and, as he leaves, she notices baby DK admiring her picture.
Klump and a group of four Kritters are marching through K. Rool's base, while, up above, Cranky is escaping the lair in a mine cart, having escaped using a nail file. He throws the file out of the cart, and it hits Klump on the head. He notices Cranky has escaped, and they chase after him. Cranky notices that the lizards are coming at him from both ways, and when the carts collide, the potion's effect wears off, leaving an old Cranky to be captured again. Cranky surrenders, and tells him that he has a proposition. He is brought before King K. Rool, and offers him the youth potion, but he does not accept, telling him that all he wants is the Crystal Coconut. He is then sent back to a prison cell.
In the jungle, Diddy is traveling to Cranky's house swinging on the vines. He reaches the hut, and through the window notices K. Rool with Cranky, demanding that he unveil the Crystal Coconut. Cranky refuses, but K. Rool still demands that he do so. Diddy then leaves, not "want[ing] to be a hero that bad..."
At Bluster Barrelworks, Candy is trying to make Donkey Kong take a nap in a barrel cradle. However, Bluster then walks in, telling her that she is "exactly three minutes and forty-six seconds" late because of her lunch date with DK. Candy explains that he never showed up, and that she is babysitting Donkey Kong's "nephew", but sees that he has escaped. He then sees him on the conveyor belt, where a barrel is made around him. She stops the machinery and takes him back to the cradle, asks him to take a nap once again, and closes the barrel around him. Bluster then gets her back to work when Cranky in hologram form appears, asking for Donkey Kong. She tells him that she does not know where he is, and that he is babysitting his nephew after he stood her up. Cranky tells her he does not have a nephew, though Candy points out the baby in the cradle. Cranky does not believe it at first, but his hologram disappears. Baby Donkey Kong then begins pounding the controls to the machines in the factory, and runs off. While Candy searches for him, Diddy returns, asking where baby DK is. Diddy notices him in a barrel, and, using the conveyor belt, chases after. He then heads outside, where several barrels that have gotten off the belt are bouncing around.
K. Rool is about to steal the Crystal Coconut back at Cranky's cabin when they hear something outside. A barrel then rolls inside the cabin and crashes into the pedestal containing the coconut, breaking the container and sending the coconut flying into the hands of baby Donkey Kong, who was inside the barrel. He begins to play with it as though it were a ball, K. Rool demanding he hand it over. Diddy then enters the cabin and "Baby Kong" throws the coconut to him. K. Rool once again demands he get it, though Diddy instead runs away, baby Donkey Kong following him. The king then has his minions follow them.
Using barrels as a disguise, Klump and his men get to DK's house. Diddy playfully asks for what he wants, and when Diddy insults him, the Kritters arm their Klap-blasters. Diddy asks DK what to do, though he instead makes gun noises. Klump believes they are actually firing upon them, and he has the Kritters return fire while he ducks inside his barrel. The Klaptraps fired then begin to chew through his floor. Klump and his men then use springs loaded into their barrels to get to the upper level right when the Klaptraps cause the section of the floor Diddy and DK are standing on to fall to the ground. K. Rool then walks up and asks Donkey Kong for the Crystal Coconut, though the baby ape refuses. K. Rool then makes a pretend game of football out of handing over the coconut, but Donkey Kong still does not hand it over. Losing his patience, he once again demands the coconut, though by then the effects of the potion wear off and Donkey Kong turns into an adult once more. Klump and the Kritters then retreat, and K. Rool tries to surrender, but Donkey Kong instead punches him in the face, causing his eye to turn bloodshot (like his game counterpart).
K. Rool is then back at his base, sulking over his latest loss. Klump tells him that they can "get him next time!" but K. Rool, calling himself old, does not believe there can possibly be a next time, while holding the youth serum created by Cranky. He believes that it can "give [him] back [his] fighting spirit," and gulps the remainder of it down. However, instead of making him younger, it shrinks him.