This is an interesting land. On the one hand, it only produces colourless mana and is Legendary, so you can only have one out at a time. But on the other hand, it does give you a creature when it dies. If you're really in a dire situation for creatures, you can play a second Gods' Eye and get two creatures for free. Combo with Crucible of Worlds and you can get two creatures for free every two turns! Now, the problem with that is that you won't be able to play any new lands if you want this to work. My personal favourite combo with this card is Crucible of Worlds, a couple Islands, a couple Hedron Crabs, and two Gods' Eyes (maybe an Azusa, Lost but Seeking to speed it up). Sure, it takes a while to set up, but it leads to a lot of shenanigans, especially if you've got the Azusa out. Now, unless you've built a deck around it, this card isn't that great as it only produces colourless and it's Legendary.
Pros: Doesn't come into play tapped, gives a creature if it dies
Cons: Only produces colourless, Legendary, good chance it won't die, needs a deck built around it to work properly
Replacements: Crystal Vein