Greater Morphling is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

: This creature gains your choice of banding, bushido 1, double strike, fear, flying, first strike, haste, landwalk of your choice, protection from a color of your choice, provoke, rampage 1, shadow, or trample until end of turn. : This creature becomes the colors of your choice until end of turn. : This creature becomes the creature type of your choice until end of turn. : This creature's expansion symbol becomes the symbol of your choice until end of turn. : This creature's art becomes by the artist of your choice until end of turn. : This creature gets +2/-2 or -2/+2 until end of turn. : Untap this creature.