Polymorphic Mob

Squad {2}{u} (As an additional cost to cast this spell,
you may pay {2}{u} any number of times. When this creature enters the battlefield, create that many tokens
that are copies of it.)
When you cast Polymorphic Mob, shuffle your
library, then exile cards from the top of your library
until you exile a creature card. Polymorphic Mob
enters the battlefield as a copy of that creature.
Shuffle the exiled cards into your library.