Wizard's Rockets enters the battlefield tapped.
{X}, {T}, Sacrifice Wizard's Rockets: Add X mana in any combination of colors.
When Wizard's Rockets is put into a graveyard from the battlefield, draw a card.
Wizard's Rockets last ability triggers no matter how it's put into a graveyard from the battlefield.
You must choose the colors of mana Wizard's Rockets produces before its last ability has you draw a card.