Ikkakumon's Harpoon Torpedo

Ikkakumon's Harpoon Torpedo is the seventh episode of both Digimon Adventure and the Digimon anime series.

Summary
The kids find themselves walking through some cold weather, and consider finding a cave they can sleep in. To their relief, there are some hot springs straight ahead, and strangely enough, a fridge full of eggs. After eating, Tai suggests climbing the nearby Infinite Mountain to get a better view of the area, but Matt argues that it would be much too dangerous. Joe prevents a fight breaking out between the two, but the matter remains undecided. So, while everyone is asleep, Joe goes off towards the mountain on his own, followed quickly by Gomamon. Whilst up there, the pair see the digimon Unimon, who is struck by a back gear. At that moment, Tai and Sora arrive on the scene to help. Joe attempts to remove the gear himself, and Gomamon ends up rescuing him by becoming Ikkakumon.