Magic Phial Pin

The Magic Phial Pin was a pin in Club Penguin and was available to all players. It was found in the Stage Underground when Norman Swarm Has Been Transformed is at the Stage.. The only way to get the pin was by finding the Stage Underground and opening the treasure chest in the room.

How to get the pin
As the Costume Trunk said on the second page, you had to stand on rocks with "X's shapes" to get to the Underground and open the Treasure Chest to get the pin.

Trivia

 * If Norman Swarm Has Been Transformed comes back to the stage, the pin will probably return as did the Ruby Pin in the play Ruby and the Ruby returned, making it the second pin to return.
 * In the play's script, it says that the Gnome has this pin, and this pin is the key to returning Norman Swarm to his original size.
 * It was Club Penguin's 105th pin.
 * It is rare.