Digimon Adventure (PSP, English Sub): Part 65: Side Quest 17
After one Sub Episode with Tai, you get another one that references a significant previous event in his life.
Back at home, Tai & Agumon received a strange email. Agumon could read it as Hikarigaoka, but Tai couldn't read that. They decided to head back to Hikarigaoka to see what they could get out of it.
Things seem to have calmed down at Hikarigaoka since the Mammon attack, but then Tai & Agumon were suddenly attacked by another, more familiar Digimon...
A PARROTMON!
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That's right! This Sub Episode is just entirely one battle that's meant to reenact the "Greymon Vs. Parrotmon" battle that happened in the Adventure Pilot movie.
And this fight can be TOUGH. Even as Agumon has a form that's stronger than Greymon at this point, taking down this Parrotmon in one piece may be quite the work to do. It's for the sake of the reenactment that no other party members are here to help Agumon out.
Don't try to be exact about that. Go ALLLLLL the way to MetalGreymon instead of sticking to Greymon, or you're likely never going to win this fight (unless you do a ridiculous amount of grinding).
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It was a tough battle, but Tai & Agumon were able to defeat Parrotmon.
Tai was able to recognize Parrotmon somewhat, but not Agumon. You'll get an item for winning this fight.
This Sub Episode doesn't affect the plot moving forward, but it was a nice wink at the very VERY first Digimon anime battle.