I have already looked at the amazing cowboy cakes on here so I have that figured out but the local vet (who mostly does large animals) is having an anniversary bbq that I've been hired to do cakes for. His assistant wants a cake that looks like his hat which is "decorated" almost always with manure. So any ideas on how to achieve this look would be appreciated.

chocolate icing ( thinned) or ganache, if you are just putting some on the hat, though it may come out looking more like mud, you could make a "cow patti" to go beside the hat to get the point across that its manure and not mud. we have cows and to be perfectly honest when it gets on your clothes it relly is just a large brown smudge so it shouldnt be too hard to accomplish.

Thanks louanne! I was kinda thinking the same thing but just thought I'd get some more ideas if anyone had any even though I'm pretty sure it's not a largely requested thing.

try crumbling a little cake and mushing it with frosting, for that "lumpy" look.