ECoin

ECoin is a sprite in bank 0 with id f9, 0 f9 x y 7

param

the param seems to be which e-coin this maps to in the overall e-coin collection

7 - Vegetable Volley
1 - Doors O Plenty

e-coin data in the e-reader level file

offset	size	description
0x0	1	e-coin index (0 if the level lacks an e-coin)
0x40	0x20	e-coin palette, same 16 bit format as any other palette
0x60	0x120	e-coin tile data, same format as tiles in the ROM

An e-coin is 3x3 tiles (24x24 pixels) and the entire coin, edges and all, is found inside the tile data. This means an e-coin can be any 24x24 pixel image and does not need to look like a coin at all. In practice the image should match the e-coin template as in-game both sides of the coin are shown, and the "e" side always looks like a coin.