This is a Yoshi Coin that will appear and be collectible only when a P-Switch is active. Thanks to Lexie for helping me refine this code.
Please note that tile 25 of whatever page you put this block on MUST be a blank tile. For example, if you put these blocks on Map16 page 4, tile 425 must be a blank tile. If you don't do this, the Yoshi Coin will act solid and leave behind an undesirable tile when collected.