Considering the fact that it costs zero mana to play, thats a hugely powerful effect
The first wave of amass cards all created a Zombie Army, but with the addition of amass orcs in LTR, the original mechanic was changed to amass zombies. This allows different sets to represent armies that match the flavor of that set
Against any agro deck he is a poor tempo play, even when you get to shoot them for three or four you will still generally lose tempo over a deck making plays that impact more on the board with their three mana
And then theres the dabbing deck, which at this point may never have enough cards
Claire D'Loon, Joy Sculptor gets around one of the fundamental drawbacks of tokens: It turns your tokens into cards, which means that they exist in other zones now
Its design space is quite large