Riot Reaper

Riot (This creature enters the battlefield with your
choice of a +1/+1 counter or haste.)
Creatures you control have riot. (They enter the battlefield with your choice of a +1/+1 counter or
haste.)
Whenever a creature you control becomes
tapped, if it entered the battlefield this turn,
Riot Reaper deals 1 damage to each creature your opponents control.