Whatever you might have to say about it, you can't say that it doesn't fit the name.

ROFL! You could also call it "Quined Sliver" :)

I'd prefer the same joke on a sliver that was not quite pointless. It doesn't quite do nothing: it can turn off Muraganda Petroglyphs on Metallic Sliver. But I think it's one of the abilities that does the closest to nothing without actually doing nothing :)

Fine then, let's make it a lot less pointless.

Two on the field give +0/+4. Three give +0+9. That's a little ridiculous. If this said "All Slivers get +1/+1 and have this ability", it would be powerful but a fine rare. Linear growth is good; quadratic growth is bad.

I think it's actually double those figures, so this gives +0/+2 by itself, then 8, 18, and 32. Toughness only is also a lot less breakable than giving a power boost.

I don't think so. It only grants itself the ability once. This is +0/+n², where n is the number of Slivers. Doran Sliver deck seems pretty good. In any Sliver deck though, it will be impossible to beat in combat.

So is Timber Protector in a Treefolk deck.

This actually works out fairly similar to Sliver Legion, doesn't it? Obviously Sliver Legion is templated in a less gratuitously mathematical way :)

If it just said "All Slivers get +0/+1 and have this ability", does that work in the rules? That is, this sliver obviously already have that ability, does it have a second copy of it (and hence a third, fourth, etc), or is "have" satisfied by the original copy of the ability? :)

@Jack (2 years ago): I suspect it doesn't work very well. It's trying to grant an ability, not just assert that a creature has an ability - see Cavalry Master. But it's granting an ability which in turn wants to grant a new ability to many things including the original permanent. I think it crashes the game trying to add an infinite number of copies of the ability to itself.