Halgex, Endless Maw

When you cast this spell, create three 3/3 green
Hydra Head creature tokens with unstoppable
and, "When this creature dies, add {b}, {r}, or {g} to your mana pool. This mana does not empty
as turns and phases end."
{1}{b}{r}{g}: Return Halgex from your graveyard
to the battlefield. Create a 3/3 green Hydra Head creature token with unstoppable and, "When
this creature dies add {b}, {r}, or {g} to your mana
pool. This mana does not empty as turns
and phases end."