Here are some suggestions:

You can actually run all of the fetch lands except Flooded Strand. As this will give you a more stable mana base, as you can go fetch your shocks/ABUR duals of the color combination that you want.

Squee, Goblin Nabob combos well with fauna shaman. You fetch for him, then you get to fetch for any other creature each turn, as you would just keep discarding squee.

Triskelion - combos with Mikaeus

Phyrexian Altar

Asceticism

Shaman of Forgotten Ways

Sheoldred, Whispering One

Filth

Urborg, Tomb of Yawgmoth - combos with filth, and helps you get triple black to cast grave pact

Buried Alive - you can go get genesis, anger, and filth

Maelstrom Pulse - gets rid of annoying permanents, especially tokens, and kicked rite of replication targets.

Volrath's Stronghold

Cavern of Souls - call dragons, so they can't counter prossh.

Also, know what you want to add/remove from the deck before you buy, as you won't be able to fit everything you want into this deck. Prossh decks have so many combo possibilities. My cousin uses Conspiracy and it opens up even more possibilities for fun.

Exactly pskinn01, which is why I made this list, to ensure I don't buy too many cards, also thanks for all the suggestions and I will address each one in turn:

• I don't want to run all the fetches because I feel like those 2 spaces could be used better in other spots.

• Good idea, Squee can be pitched to everything and makes a comeback.

• Maybe? Depends on how much space is left. I think I have enough tudors for it, but without Mikaeus, he's really bad.

• Already in.

• Again, Maybe? The protection is nice, but is unsure whether it is worth a slot.

• Sadly no, Somberwald Sage and Black Market/Thran Dynamo are just better. The Biorhythm scares me a bit too.

• Sheoldred, Count me in! I feel the would be a great add on to this deck.

• Filth and Urborg... hmmm. I would say not, not because I don't like unblockable stuff, I just can't guarantee that I draw the Urborg to make it worth it.

• Buried Alive, maybe? Again. Have to look at the slots when I finish the final product.

• Maelstrom Pulse get in here! Premium removal is always a good thing.

• Stronghold seems worth, so it's in.

• and I would say no to Cavern of Souls because if Prossh gets countered, I still get the tokens anyway, so it isn't a big loss for me. Defense Grid covers that front well too.

Thanks for all the help. I greatly appreciate it.

You an take a look at my prossh deck, it runs really well against my playgroup Junds of Fun.
Keep in mind i don't use inf combos.

Easier, I'll link my prossh build and you can check it out for yourself.

I TRIED for casual; I failed

Prossh might be my fav deck of all time. Check out my list below. Mine used to be very combo heavy.

Prossh, the Magnificent King under the mountain