You put a +1/+1 counter on Ravenous Gigamole if you don't put a creature card into your hand with its ability, even if there wasn't a creature card among the milled cards.
2022-10-14
If a replacement effect causes the milled cards to be exiled rather than go to the graveyard, this effect can still apply to the cards "milled this way" in exile.
When this creature enters, mill three cards. You may put a creature card from among the cards milled this way into your hand. If you don't, put a +1/+1 counter on this creature. (To mill a card, put the top card of your library into your graveyard.)
