Momo, the Rattlesnake

Tribute 3 (As Momo enters the battlefield, an
opponent of your choice may place three +1/+1
counters on it.)
When Momo, the Rattlesnake enters the battlefield, if tribute was not paid, you gain 4 life.
—
Be warned, one gaze into the eyes of Momo,
and you will be hypnotized for all eternity.