Well, the Let's Make A Tileset project for August was a huge (IMO) success, so here we go again for September! First, I'll copy in the rules from last time:

• Each update to the tileset must contain at least one new tile.
• There are no official color restrictions. You may draw in 8-bit, 16-bit, or however you want. At the end of August September, Tilesetpal will be used to attempt to reduce the tileset to a reasonable number of colors if it is an issue.
• When updating the tileset, you may also edit existing tiles - this includes changing the colors, making them bigger, fixing small bugs, changing the shading, etc. You may only edit a tile if it is still recognizable as the same tile once you are done with it. Never redraw an existing tile from scratch.
• You may alter the tile order as little or as much as you want when updating the tileset.
• Do not include a Palette tile. This will be added when the tileset is complete. However, it may be advisable to leave a blank tile for the palette to go into.
• Please refrain from posting textured backgrounds until at least the 20th of August September, so we have an idea of what the tileset is like. Eventually, one textured background (if more than one are submitted) will be picked to be used in the tileset.
• If you really do not want some of your tiles to be edited, for whatever reason, specify this clearly.
• Don't worry about masking. I (or a helpful volunteer if one exists) will compile a mask for the tileset at the end of August September. If I (or the volunteer) am unsure of how to mask a tile, and no instructions were provided in the post that introduced the tile, the creator of the tile will be contacted about it.
• Logical content rules apply. Do not use the tileset to contain attacks against other people, pornographic or oherwise illegal images, links to illegal web-sites, or stuff like that. Use your common sense.
• Enjoy, and don't be afraid to ask questions!

And here's (again) two fairly ugly tiles to start you off with. Feel free to add onto or edit them as much as you want.