Wormhole Activation

Put a Leviathan Token 4/4 with flying on the
battlefield.
Flashback {4}{g}{w} (You may cast this card
from your graveyard for its flashback cost. Then
exile it.)
An Einstein-Rosen bridge, also known as a
wormhole. In layman's terms, a portal to another
universe opening below the ozone layer."
—Phil Coulson