Things You'll Need
Instructions
Insert your Action Replay device into your Nintendo DS and plug "Pokemon Diamond" into the Action Replay. Turn on your Nintendo DS and let it load to the Action Replay home screen.
Press the Code Select button in the lower-left corner and select "<Add New Code>" at the top of the list. Name the code using the onscreen keyboard, something easy to remember like "Wild Cyndaquil." Press "Next" when you've entered a name.
Type "94000130 fffb0000 d5000000 0000009b b21c4d28 00000000 b0000004 00000000 c0000000 0000000b d7000000 00024620 dc000000 00000006 d2000000 00000000" into the "Enter New Code" screen and press "Next" when finished. Ensure that the code is enabled before pressing the Start button to launch "Pokemon Diamond."
Start your game and go to an area where you can encounter wild Pokemon, such as the grassy areas. Walk around until you get into a Pokemon battle.
Fight the wild Cyndaquil until his health is almost gone. Throw a Pokeball at Cyndaquil and, if his health is lowered enough, you'll catch him.