Firemaw Kavu [Time Spiral]

Echo {5}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Firemaw Kavu enters the battlefield, it deals 2 damage to target creature.
When Firemaw Kavu leaves the battlefield, it deals 4 damage to target creature.