Serpent of 3 Heads

Trample
Empty {2}{g/w}{g/w} (You may cast this card for its empty cost. If you do, exile it as it resolves. During your precombat main phase, if an opponent cast no spells last turn, you may cast the exiled card without paying its mana cost. Empty only as a sorcery.)
If Serpent of Three Heads would die, instead exile it and create two 3/3 green and blue Serpent creature tokens.