FYI: White has 5 cards that give you hexproof (Aegis of the Gods, Imperial Mask, Leyline of Sanctity, Spirit of the Hearth and Shalai) and 3 that give you shroud (Ivory Mask, Solitary Confinement and True Believer). 2 artifacts for hexproof (Witchbane Orb and Orbs of Warding) and one green card for shroud (Form of the Squirrel) close the lot.

FYI

My birthday was last week, but apparently my question drowned in your popularity. So... will we ever see another card in the spirit of Form of the Dragon or Form of the Squirrel, that allows a planeswalker to "transform" into some thematically appropriate creature?

Both were complex, but I could see us visiting it again some day.

Un Rules Question. Is the "You lose the game when it leaves play" clause of Form of the Squirrel something inherent to the token, or an effect of the enchantment? If The enchantment is destroyed are you still that squirrel and lose if it leaves play?

The “lose the game” ability is part of the creature token. If the only Form of the Squirrel enchantment gets Naturalized, but the token is still on the battlefield, you do not lose the game.

Did you ever think of doing Form of the Ass for Unhinged?

Form of the _________ is funnier if you are already familiar with the thing you’re becoming. It was always Form of the Squirrel.

Form of the Squirrel will not stop you activating Isochron Scepter & Elite Arcanist, but it will stop you casting the copies.

This is correct. I misunderstood the point of the original question.

What are the chances of us seeing the formation of a cycle of cards to go with Form of the Dragon? I'm a huge fan of the card, since it is powerful and also flavorful. Getting to see a series of enchantments like that in the other 4 colors would be really exciting.

Green got one in Unhinged - Form of the Squirrel. We have no current plans for a Form of ______ cycle.

What is your opinion on Form of the Squirrel? Do you like it because of squirrels, or dislike it because green isn't supposed to change things into other things?

Changing a player is very different than changing a creature flavorwise. Note that I don’t complain about Form of the Dragon because red doesn’t polymorph.

Hypothetically, if I were playing a game of Silver-Bordered Magic, and I had access to a live squirrel, and I put that squirrel onto the table after playing Form of the Squirrel, but then the Squirrel ran out of the room amid the resulting pandemonium. Do I lose the game? I image as silver bordered rules manager you get asked that a lot.

As much as it saddens me, I cannot officially condone the bringing of a live squirrel to a Magic event (They’re basically rats with better PR if you’re unaware.)