(To be more precise, the "becomes a green Snake" is in effect on layer 4, the "loses all abilities" is in effect on layer 6, and the 1/1 power/toughness setting ability is in effect on layer 7b.) So Snakeform will make it a 1/1 green Snake with no abilities regardless of whether it transforms or not
Krosan Beast is a good example of this, with its transformation from a lowly 1/1 Squirrel into a massive 8/8 Beast, and the hatching of Rukh Egg is another
Doomsday Excruciator They finally did it, the ultimate mill card for 100-card decks
Unless the card in question is an instant or a sorcery type, that text will be divided up into individual abilities, describing the effects it has while in play or (more rarely) when in another zone like the hand or graveyard
Honorable Mention #3 - Into the North With the printing of a set of dual lands that have various types that are all about that Snow-ness, Into the North is better than ever before