Good Day to you,
I've created a bunch of 2d isometric fantasy sprites, see my website for details, they are free for you to use in any games commercial or otherwise.
You will need to use a program on my website to export from my own format to either BMP with a mask colour (specified by the user) or as TGA with an alpha channel.
Each sprite has hundreds of frames of animation in either 8 or 5 directions (those with 5 can be flipped in the program to represent the missing 3 directions to make 8).
Here are a few sample images:
Hope you get much enjoyment out of these.