if you end up splashing green (for ramp and whatnot), then
Craterhoof Behemoth might be the best option. Since it triggers on ETB, it all each other creature you pull from
Indomitable Creativity will all get the buff, plus any creatures left over. And since Craterhoof has haste and trample, it can usually be enough to end things then and there. Plus, if there's enough ramp in the deck (from mana dorks and mana rocks, you could jst end up hard-casting him.
Craterhoof Behemoth would be my favorite hit off
Indomitable Creativity, but if you're looking for others, these are all pretty sweet:
Platinum Angel: if they can't kill it, you win
Platinum Empirion: can usually stall long enough to just beat them to death with it
Massacre Wurm: Great against creature decks and can sometimes kill your opponent out of nowhere.
Elesh Norn, Grand Cenobite: Another sweet anti-creature card since it shrinks all your opponents creatures and makes your army big on the spot.
Something like
Lightning Greaves could be sweet in this deck, since it gives whatever you find haste, and protect it from removal, and worst case, you can just sack it to
Indomitable Creativity. Just something to think about, good luck!