When Firegantuan Kavu enters the battlefield or you cast a red instant or sorcery spell, you may have it deal 2 damage to target player.
When Firegantuan Kavu or another red creature you control dies, you may have it deal 4 damage to target creature.
See Challenge # 131.
Woo, lets see if we can make Flametongue Kavu even splashier!
Haha, cool!