Niv-Mizzet, the Firemind

Flying

Whenever Niv-Mizzet deals damage to a player, you may draw a card.

: Niv-Mizzet deals 1 damage to any target.

This spell can't be countered.

Flying

Whenever you draw a card, Niv-Mizzet deals 1 damage to any target.

Whenever a player casts an instant or sorcery spell, you draw a card.

Slivers you control have flying and "Whenever you draw a card, this creature deals 1 damage to any target" and ": Draw a card."

Flying

You have no maximum hand size.

Whenever a source you control deals noncombat damage to an opponent, you draw that many cards.

Flying

Whenever a Dragon you control is dealt damage, it deals that much damage to any target that isn't a Dragon.

Flying

Whenever this creature attacks, you may pay . If you do, it deals X damage to any target.