Core!Frisk, Hotel retreiver

When Core!Frisk enters the battlefield, until end
of turn, whenever a creature enters the battlefield,
you may pay 1. If you do, put a +1/+1 counter on
Core!Frisk and draw a card.
Retrace.
When Core!Frisk enters the battlefield, if it was
cast from the graveyard, you may pay 3. If you
do, return target creature card from your
graveyard to your hand.