Hogwarts Express

Whenever Hogwarts Express attacks, create a Treasure token for each creature that crewed
it this turn. (They're artifacts with "{t}Tap, Sacrifice this artifact: Add one mana of any
color.")
Crew 1. Activate only once each turn.
(Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)