Murderous Redcap + First Day of Class

Steps

1. Cast First Day of Class by paying {1}{R}.
2. Cast Murderous Redcap by paying {2}{B/R}{B/R}.
3. When Murderous Redcap enters the battlefield, it and First Day of Class trigger.
4. Resolve the First Day of Class trigger, putting a +1/+1 counter on Murderous Redcap.
5. Resolve the Murderous Redcap trigger, dealing an amount of damage to itself equal to its power.
6. Murderous Redcap dies as a state-based action due to having 0 toughness.
7. Murderous Redcap's persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
8. Repeat from step 3.