In EDH if I {Green Sun's Zenith} a {Vastwood Hydra} can I pay X to have the hydra come in with more counters.
Say I cast GSZ for {6}{G} does my hydra come in as 4/4?
Unfortunately everywhere but the stack X is 0, so you could find it, but you don't get a chance to assign X to a number and will enter as a 0/0
On the plus side you would only have to pay {2}{G} to find it :)