Instructions
Fight with any of your Digimon that has an Obedient Personality. This information will appear when checking your Digimon's stats via the in-game main menu. Send this Digimon into battles, until it has an Attack stat of 300 or more.
Go to Digi-Central, the first place you visited when the game began. Speak with Gatomon, who is in the room with Mr. Gure. Select the "Matching via WFC" option, when prompted by Gatomon.
Enter the room with Gatomon on a second Nintendo DS with a copy of "Digimon World." On this copy of the game, the player must have any Dragon-type Digimon with any level and stats. Select the "Matching via WFC" option.
Follow the onscreen prompts to match your Digimon with the other player's Dragon-type Digimon. Watch the short animation. When you regain control of the game, you will have a Serpent Egg.