This card doesn't get enough credit for how awesome it is. This can easily win you the game if you have a Selesnya-coloured deck. Here's how:
Play Tireless Tribe
Give Tireless Tribe +0/+4 by tossing this
All your lands are now Savannah in addition to their other types
Read that last line again. All your lands are now Savannah in addition to their other types. Well, I lie a little bit when I say that since they're neither Plains nor Forests so those pesky Graceful Antelopes and Shanodin Dryads aren't unblockable for you. This card allows you colour-fix your deck really easily if it's in you graveyard but therein lies the problem with this card: getting it into your graveyard. Green and white aren't short on spellshapers but there aren't as many cards that cause you to discard in these colours as there are in, say, black (maybe this is where Anurid Brushhopper can shine?). Still, the sheer potential of this card is astronomical, especially in formats like EDH.
Pros: All your lands become pseudo-Savannahs if in your graveyard
Cons: Slight problem getting it into your graveyard