Nonk, Goblin Suicide Bomber

Nonk, Goblin Suicide Bomber enters the battlefield with X Powder counters on it, where X is the amount of mana spent to cast it.
Whenever Nonk deals combat damage, you may sacrifice it. If you do, Nonk deals damage equal to the number of Powder counters on it to all creatures blocking it and/or the player or planeswalker it dealt combat damage to.