ClayCraft is a texture pack made by Dableo. It attempts to give Minecraft a look as if it was made out of clay. Most blocks and icons have been altered. An overview:
Mobs have also been altered and personally: I like their new look.
I really do like the new icons in this texture pack.
And some more screenshots:
Download this texture pack (128x): http://j.gs/YSx
Download this texture pack (64x): http://j.gs/YSw
Topic on minecraftforum.net: http://j.gs/YSv