Erica, Curator of Carnivores

Whenever a nontoken dragon enters, create a green and white 3/3 dinosaur creature token with trample.

Whenever a nontoken dinosaur enters, create a red 2/2 dragon creature token with flying.

Whenever another nontoken human enters, creatures you control gain trample.

{w}{r}{g},{t}: Return target dinosaur or dragon creature card from your graveyard to your hand.