Croagunk Special Encounter

==Information==
Location: Citrine Mountain
Available: After Badge 03
==Guide==
You need to obtain the Silver Ring from the Beryl Gym to obtain this Pokemon. If you haven't obtained it, click "Expand" to get the guide on how to get it. If you have already obtained it, skip to the next step.
First, you need access to the secret room, which involves solving the tube puzzle in Beryl Gym. The puzzle differs in two cases. 
* If you have not found all five police officers before fighting PULSE 05A - Tangrowth (Police Farce), the puzzle will start like in the left photo. Your goal is to turn all tubes into red.
* If you have found all five police officers before fighting PULSE 05A - Tangrowth (Police Found), the puzzle will start like in the right photo. Your goal is to turn all tubes into blue.
The steps to solve the Police Farce version is as follows. The photos show the result after the action in the caption is taken.
Click the tube in the bottom left corner. Then click the tube in the bottom right corner.
The steps to solve the Police Found version is as follows. The photos show the result after the action in the caption is taken.
Click the tube in the bottom right corner. Then click the tube in the top left corner.
Click the tube in the middle of bottom row. Then click the tube in the top right corner.
After you defeating Corey and witness the events of the Wasteland Wall, the Silver Ring will appear in his room.
The photos show the positions after the actions are taken.
Go to Citrine Mountain from the entrance opposite to Yureyu Power Plant. Go down from the entrance.
Go down and left. Then go down and right.
Go down and right again. Then go down and left. Showing Croagunk the Silver Ring will prompt it to join the party. Croagunk has the Egg Move in its moveset. If you check the summary of Croagunk, it says the original trainer was Corey.