Overgrown Hydra

Trample
Overgrown Hydra is green.
Only spend {g} to cast Overgrown Hydra. It enters
the battlefield with X +1/+1 counters on it.
If Overgrown Hydra enters the battlefield with 3
or less counters on it it gains haste until end of
turn.
As long as Overgrown Hydra has 4 or more
counters it has hexproof from all but green.