Crackling Tide Hydra

Crackling Tide Hydra enters the battlefield with
X +1/+1 counters on it. Where X is the amount
of mana spent to cast it.
When Crackling Tide Hydra is cast, look at the
top X cards of your library, where X is the extra
mana spent to cast it. You may put them back on
top of your library in any order you choose.
Remove a counter from Crackling Tide Hydra
and add {u} or {g} to your mana pool.