new ability from Return to Ravnica: Unleash

Unleash (You may have this creature enter the battlefield with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Example card:



Grim Roustabout 1B
Creature- Skeleton Warrior (Common)
Unleash (You may have this creature enter the battlefield with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
1B: Regenerate Grim Roustabout.
1/1