Gremag, Unbound Mountain

Surge {x}{w}{r}{g}
When Gremag, Mountain Unbound enters the battlefield, up to three target creatures you
control get+3/+3. If it's surge cost was paid,
instead up to X creatures you control get +X/+X.
Pay 3 life, {t}: Add {w}, {r}, or {g}. If this mana is
used to cast a creature spell, it gains haste.