Rampaging Rendhorn

Creature — Beast

Riot (This creature enters the battlefield with your choice of a +1/+1 counter or haste.)

4/4

2019-01-25:
Riot is a replacement effect. Players can’t respond to your choice of +1/+1 counter or haste, and they can’t take actions while the creature is on the battlefield without one or the other.
2019-01-25:
If a creature entering the battlefield has riot but can’t have a +1/+1 counter put onto it, it gains haste.
2019-01-25:
If you choose for the creature to gain haste, it gains haste indefinitely. It won’t lose it as the turn ends or as another player gains control of it.