Oran-Rief Ooze

When Oran-Rief Ooze enters, put a +1/+1 counter on target creature you control.
Whenever Oran-Rief Ooze attacks, put a +1/+1 counter on each attacking creature with a +1/+1 counter on it.

Foundations Jumpstart

Magic Online Promos

Zendikar Rising Promos

Zendikar Rising

Oran-Rief Ooze can be the target of its own first ability.

The group of creatures that receive a +1/+1 counter from Oran-Rief Ooze’s second ability is determined only as the ability resolves. Other abilities that trigger on attacking (such as that of Paired Tactician) may add counters to creatures before that ability resolves.