Furfle, Goblin Technician

{x}{u}{b}{r}, {t}: Entrap the top X cards of your
library. (Put those cards onto the battlefield face
down as 0/1 Mine artifact creatures with defender
and "When this creature would die, instead turn it
face up and exile it. If it is a nonland card, cast it
without paying its mana cost." Players may not look
at those card while they are face down.)
"BOOM! Hehe... What?! We don't make jokes
anymore 'round here?! Pheh..."
~Furfle, Head Technician of Snab Explosives