[Ducky]

I would be worried by the lack of protection from removal, especially if you're playing it where one creature getting big is your win condition. If you're going for a swarm condition then removal isn't as big of an issue.
I would suggest looking into some other equipments, like mask of avacyn or either of the hexproof/shroud boots. then there's little ones like bladed bracers that give additional things when on humans.
Otherwise it seems fairly solid and should get a fair amount of creatures out pretty fast. Though that may lead to a fairly limited hand size quite fast, with only one card in the whole deck to help with that.

Really though i could say all sorts of things, but i can't really see it or really guess how it will play. you just have to play test it a lot.